bluuebunny/crossref_metadata_2025 huggingface dataset:
Making Wells Safer; Rectification of High Annulus Pressure via Diagnostic and New Technologies Through Annulus Intervention Method
Authors: Osman Abdul Afif , Azman Aulfah , Sipangkui Rayner Brian , Nazirmuddin M Nazrul Shahril , Aripin Izura , Utta Arie Muchalis , Sujavudin M Ridhuwanuddin , Sy Ahmad Sy M Shahril
Published: August 2022

Sustained annulus pressure is an increasingly common well integrity issue encountered particularly in aging platforms. The issue is normally discovered via periodic wellhead maintenance programs or during monitoring by the production team. Subsequently, the wells integrity team will pursue well diagnostic via annular pressure diagnostic by manipulating and creating specific conditions to acquire information on the potential leak rate, leak path, and source of the leak. The probable culprit of the tubular integrity issues is due to completion or casing leakages, or failed cement conditions.

The generic rectification technique available varies from rig to rigless method. Considering the low economic of the field & remote jacket location with a small footprint and limited crane capacity in Sabah waters, either the rig or workover option can be unfavorable. Therefore, the options available to remediate the sustained annulus pressure are limited considering the platform's design and operational setup. Historically, the team has attempted with a conventional pump and lubricate the annulus to mitigate the symptoms. However, the effectiveness was questionable as the pressure kept creeping up within a short period which urged the team to look into better technology solutions.

With the limitations above, the team warrants a new holistic approach to resolve the sustained annulus issue. Annulus Intervention System (AIS) provides better fluid conveyance and circulation for better fluid displacement at the targeted depth. The AIS system has a smaller footprint as compared to a pumping or workover unit which is a major advantage for a small and remote platform directly applicable to the target Sabah asset. This paper will table out the step-by-step method that has been taken by the team to ensure the AIS system is engineered and tailored to rectify the sustained annulus pressure in a less than 500-meter square deck space.
Storage Development Plan SDP for Abandoning High Risk Development Wells and Drilling Fit-For-Purpose CO2 Injectors Offshore Carbon Capture Storage CCS Project
Authors: Picha Mahesh S , Chuttani Anil
Published: August 2022

Operators are majorly focusing on zero carbon emission to comply environmental rules and regulations. This paper aims to give insights on world's major CCS project Storage Development Plan (SDP), where CO2 injection wells will be drilled to inject, and store produced CO2 from contaminated fields. To safeguard the CO2 storage containment, the integrity of all wells needs to be scrutinized. Ensuring long-term wells integrity of existing Plug and Abandonment (P&A) and active wells that penetrated the selected CO2 storage reservoir is the key to reduce leakage risks along the wellpath for long-term containment sustainability.

Development wells in the identified depleted gas field are more than 30-40 years old and were not designed with any consideration of high CO2 concentration in the reservoir. Possibility of leakage along the wellbores due to accelerated corrosion, channeling, cracks, cannot be ignored and requires careful evaluation. Rigorous process has been adopted in assessing the feasibility for converting existing producers into CO2 injector. Wells disparity between the required defined basis of designs for gas producer and CO2 injection wells governs the re-usability for CO2 injection or needs to be abandoned. New three (3) CO2 injectors with fat to slim design approach, corrosion resistant alloy (CRA) material and CO2 resistant cement are designed in view to achieve lifecycle integrity. Optimum angle of 60deg and maintaining the injection pressure of 50 bar at 90MSCFD rate is required for the injection of supercritical CO2 for 25 years. On top, during well execution, challenges such as anti-collision risk, total loss scenarios while drilling in Carbonate reservoir needs to be mitigated. The completion design is also focusing on having minimal number of completion jewelries to reduce pressure differential & potential leak paths all the way from tubing hangar down to the end of lower completion. Well design optimization from fat to slim has been carried out based on WellCat sensitivity analysis output. Well integrity life cycle monitoring using in country value latest generation fiber optic as well as acquiring seismic for CO2 plume development.
Research and Application of Integrated Technology of Chemical Sand Control and Stratified Water Injection in Offshore Oilfields Injection Well
Authors: Zhao Shunchao , Zhou Yugang , Bai Jianhua , Fang Tao , Shang Baobing
Published: August 2022

This paper proposes an integrated technology of chemical sand control and stratified water injection in water injection well, which enlarge the inner diameter of injection well after sand control and achieve flexible stratification of injection layer. Mechanical sand control is the main method for injection wells in offshore oilfields. After sand control, the inner diameter of injection well is small and the number of injection layers is generally 3-4 layers. For reservoirs with strong longitudinal heterogeneity, it's difficult to get higher longitudinal sweep coefficient of driving and better effect of injection.

The technology realizes completion by chemical sand control, without screens downhole. The ceramsite whose surface has been treated by crosslinking agent is injected into the well and heated. The crosslinking reaction occurs on the surface of the ceramsite, forming a cement layer with a thickness of 3-5cm and a certain compressive strength of 7.2MPa and a permeability of 5000mD on the wellbore. This cement layer not only can be used as a barrier to retain formation, but also can provide flow channels for fluids. Then, the stratified injection pipe string is run. The developed multi-functional packer contacts and seals the cemented layer to realize the stratification of the injection reservoir. The position and quantity of the packer are designed according to the target injection horizon to achieve flexible stratification.

This technology has been successfully applied to 4 wells in the Bohai Oilfield, all of which have the characteristics of large reservoir thickness and strong vertical heterogeneity. The conventional sand control and injection technology makes it difficult for the actual injection volume to reach the target volume, and the water cut of the benefit well continues to rise. After applying the integrated technology, for a directional well with a bore diameter of 9.625 in, the maximum inner diameter can reach 9.625 in, while the inner diameter of traditional sand control methods is only 4.75 in. The number of injection layers exceeds 5, and the actual injection volume meets the designed requirement. The validity period has exceeded 40 months and continues to be effective. The water cut of the benefiting well decreases from 85% to 78%, and the oil production rate increased from 56 m3/d to 72 m3/d.

The successful application of the integrated technology provides a new idea for subdivision water injection in offshore oilfields. The increase in the internal diameter of well can reduce the difficulty of operation and increase the water injection rate. The flexible stratification can improve the vertical production degree of reservoir water flooding and the overall effect of water injection.
Application of DNN-TCN Composite Neural Network in Rate of Penetration Prediction
Authors: Zhou Fei , Fan Honghai , Lu Baoping , Zhang Hongbao , Raj Infant , Tao Xingang , Bai Kankan
Published: August 2022

Rate of Penetration (ROP) prediction is the theoretical core of drilling tool selection and drilling parameter optimization. In recent years, researchers have proposed a variety of ROP prediction models, which can usually be divided into the following two types: traditional empirical and theoretical formula methods, and methods based on data-driven or machine learning techniques. However, the above methods only consider the engineering or formation parameters corresponding to the depth to be drilled, while ignoring the force and motion state of the drilling tool of thousands of meters in the irregular wellbore, which makes it difficult to improve the prediction accuracy of the ROP and can't meet the requirements of drilling parameter control in the era of intelligent drilling.

This paper proposes a DNN-TCN composite neural network that can handle both non-sequential features and sequential features. The DNN-TCN model not only considers engineering and geological parameters (non-sequential features: weight on bit, revolutions per minute, gamma ray, etc.), but also considers the force and motion states of drilling tools in the wellbore (sequential features: deviation angle, azimuth angle, dog leg, borehole size, diameter of drilling tool, etc.). The first branch of the DNN-TCN model is DNN, which is used to process non-sequential features; the second branch is TCN, which is used to process sequence features. Using a fully connected neural network to fuse the output layers of branch one and branch two, a new network structure can be obtained—DNN-TCN composite neural network.

This paper collects data from 50 wells in a specific field to train and test the model. Root mean squared error (RMSE) and a self-definition indicator which named average accuracy (AA) are adopted to evaluate models performance. The results show that the DNN-TCN composite neural network has higher prediction accuracy than traditional theoretical/empirical models and others machine learning models. In addition, because the DNN-TCN model considers the force and motion state of the drilling tool in the wellbore, the accuracy of the ROP prediction for directional wells is greatly improved, which can't be achieved by other models. That is to say, the DNN-TCN model can have better performance, and the model has good universality.

The DNN-TCN model combines the following two capabilities: 1, The powerful nonlinear mapping ability of Deep Neural Networks (DNN) in dealing with high-dimensional complex problems; and 2, The long-term memory ability of Temporal Convolutional Neural Network (TCN) in dealing with sequence problems. The model considers the force and motion state of the drilling tool in the wellbore, and effectively improves the prediction accuracy of the ROP. It is an important basis for drilling tool optimization, drilling parameter design and real-time optimization, and helps to improve the intelligence level and construction efficiency of drilling engineering.
Study on Dynamic Variation Characteristics of Reservoir Fluid Phase Behavior During CO2 Injection in CO2 Based Enhanced Oil Recovery Process
Authors: Zuo Mingsheng , Chen Hao , Xu Chenghao , Stephenraj Infant raj , Qi Xinyu , Yu Haizeng , Liu Xiliang Yang
Published: August 2022

CO2 huff and puff is an effective EOR technology for tight reservoirs. However, the mass transfer between CO2 and oil makes the reservoir fluid phase behavior very complex and affects the reservoir recovery. Through the visual injection experiment, phase equilibrium calculation model and thermodynamic parameter entropy, this paper researches the change characteristics of oil phase behavior during CO2 injection. In this paper the oil phase behavior is divided into four stages and reveal the mechanism of oil phase behavior changes. The results show that in the first stage of CO2 injection, CO2 dissolves in the oil and the volume of oil expands. In the second stage, CO2 dissolves, replaces and extracts the components of the oil, forming the third phase oil-gas transition zone, so that the volume of the oil decreases rapidly. In the third stage, the mass transfer of oil-gas components slows down, and CO2 extraction effect becomes the main factor, so the oil-gas transition zone almost disappears, and the volume of the oil decreases slowly. In the fourth stage, the mass transfer of oil and CO2 stops, and due to the compression effect the volume of oil decreases linearly. Because of the effects of extraction and compression, excessive injection of CO2 is not conducive to enhanced EOR. These results can furnish an in-depth understanding of the complicated mechanisms of the CO2 huff and puff in unconventional reservoirs.
Multi-Stage Length Optimization with Integrated Hydraulic Fracture Propagation and Production Simulation Technology for Horizontal Wells in Unconventional Resource
Authors: Yuankai Xiang , Zhou Jianlin , Leiming Cheng , Junxiu Ma , Huang Xingning , Singjaroen Thanapol , Kieduppatum Piyanuch
Published: August 2022

Since the tight sandstone gas reservoir which is widely distributed in China has become increasingly important in oil field with the further development of resource, it is extraordinarily meaningful for the sustainable and healthy development of China’s energy industry to explore its benefit development mode. Though great achievements have made with the wide use of the hydraulic fracturing technology, which serves as an effective process measure to increase the productivity of a single well, in the development of global unconventional oil and gas resources, there have been many technical problems exposed. A critical one is that if the fractured stage length is too long, the oil and gas resources won’t be effectively exploited, and if it is too short, the operation cost and time will be increased apparently. Therefore, it is urgently required to make plans for determining the optimal length of the fractured reservoir based on different geological features of the oil and gas reservoirs. This paper took the tight oil reservoir in Lower Wuerhe formation in study area as the research case, determined 5 fracturing stage length cases combined with the treatment status and pumping injection procedure of M oil field: Case A (40m), Case B(50m), Case C (60m), Case D (70m) and Case E(80m), and realized fully 3D coupled simulation of the hydraulic fractures in H1 well based on the 3D geomechanical modeling and 3D DFN model with considering multiple factors including stress shadow, proppant settlement and migration using the unstructured grid technology to preprocess it to improve the capacity prediction accuracy of numerical simulation. The productivity prediction results showed that the 10-year EUR (Estimated Ultimate Recovery) of a single well ranged from 35,500 tons to 48,200 tons. With the comprehensive production and fracturing operation cost being considered comprehensively, it was recommended that the optimal length of the single fractured reservoir should be 60 meters.
Well Integrity Under Dynamic Stresses Using Flexible Cement Systems
Authors: Mahmood Ahmad Abdullah , Rasheed Hassaan , Jan Usman Ahmed , Khan Anum Yousuf , Salazar Jose
Published: August 2022

As the field of well construction has advanced over the years, one feature that has remained consistent throughout is the use of Cement as a primary well barrier element. The long-lasting, impermeable nature of the cement matrix means no other material has been considered as an effective, widely-available alternate almost a century from the first cement job. What has changed however, with advancement in the the field of well integrity, is how we approach the cement job design and how certain materials can complement the role of the cement in improving hydraulic isolation. The historical cement job design only targeted a pumpable slurry reaching the desired placement interval, then the design moved to improving liquid slurry properties such as rheologies, fluid-loss and free fluid. Later, the short-term performance as the slurry transitioned through a gel phase to a set state also became an important criterion. More recently, after the renewed global focus on well integrity as learning from disasters such as Macondo, the annular cement’s role as a well barrier has become a major focal area for any well construction program.

This paper presents a systematic approach in designing cement systems that promise long-term well integrity starting with the root-cause identification, simulating the effect on the cement sheath, required modification of the design, and finally the application and associated results.
Cable Deployed ESP System Applied with Conventional ESP Assembly: A New Generation of Rigless ESP Technology
Authors: Zhao Mengpan , Zhang Qiang , Wei Ping , Hong Yuandong , Li Qijun , Zhu Lisha
Published: August 2022

A new generation of Rigless ESP technology, Cable Deployed ESP (CDESP) System uses specialized cable to replace ESP, which saves rig cost and reduces production deferment tremendously. However, most CDESP in the market are applied with inverted ESP assembly, which has high requirements and more uncertainties on customized ESP.

This paper will introduce the design philosophy of a CDESP applied with conventional ESP assembly, which is more compatible. Rounds of multiple factory tests were successful, pressure test of hanger assembly and penetrator system were up to 7,500 psi,cable connector tension tests meet the specialized cable and ESP weight requirement. Also, the electrical tests were qualified. The factory tests and field applications verified the reliability and robustness of this new generation of Rigless ESP technology.
Pilot Deployment and Field Validation of Wellbore Strengthening Design Criteria and Enhanced Fracture Gradient in a Depleted Reservoir
Authors: Tan Chee Phuat , Razak M. Solehuddin , Zakaria Siti Shahara , Abitalhah Abiabhar , Wan Mohd Zainudin Wan Nur Safawati
Published: August 2022

Fracture gradient enhancementtechnology has been developed for drilling mud compounds based on comprehensive large scale laboratory test data which can widen the stable mud weight window for safe and efficient drilling in depleted reservoirs. Based on the laboratory test data, correlations were developed between optimum compound particle size against Young's modulus of the rock and generated fracture width for maximising the wellbore strengthening performance of the compounds. In addition, Enhanced Fracture Gradient (EFG) concept and criteria were developed for the compounds to widen the stable mud weight window. The niche workflow developed for utilisation of the wellbore strengthening design criteria and guidelines was deployedand validated in the pilot deployment of the optimum compound particle size correlations and Enhanced Fracture Gradient criteria in two wellsfor drilling through a depleted reservoir in the Malay Basin.The enhanced fracture gradient was predicted and incorporated into the mud weight programme and mud loss contingency plan of the wells. The wells were drilled with 10 ppb of the optimum mud compounds and the concentration was monitored and maintained throughout the drilling. In the first well, the maximum ECD exceeded the in-situ fracture gradient of the depleted reservoir by 1 ppg without any losses. Following TD of the hole section, an openhole leak-off test was conducted which validated the predicted average EFG of 1.8 ppg above the in-situ fracture gradient. The predicted EFG was within 0.2-0.3 ppg from the openhole leak-off test value. In the second well, the depleted reservoir was exposed to 0.6 ppg above the in-situ fracture gradient and no losses was observed.
Locked up at home : A cross-sectional study into the effects of COVID-19 lockdowns on domestic violence in households with children in Belgium
Authors: Fomenko Elizaveta , De Schrijver Lotte , Vandeviver Christophe , Keygnaert Ines
Published: August 2022

Background
Policymakers worldwide took measures to limit the spread of the COVID-19-virus. While these sanitary measures were necessary to fight the spread of the virus, several experts warned for a significant impact on mental health and a potential increase in domestic violence. To study the impact of the COVID-19 measures in Belgium, and the factors influencing the occurrence of domestic violence, we set up the study on relationships, stress, and aggression. In this study, we evaluate the prevalence of domestic violence victimization during the COVID-19 lockdown in Belgian children aged zero to seventeen years and the associations of the parents’ financial status, relationships, mental health, and previous victimization to the child’s victimization.
Methods
A stepwise forward binary logistic regression was used to analyse the association between multiple risk factors of domestic violence and victimization of the respondent’s child. The respondent being an assailant, the respondent’s age, and the age of the children in the household were added as moderators.
Results
In this model an association with domestic child abuse was found for the age of the respondent, the household’s size, the presence of children between zero and five years in the household, the perceived stress level of the respondent, and victimization of the respondent during the first wave of the sanitary measures, as well as victimization before the COVID-19 pandemic. None of the interacting effects were found to be significant.
Conclusion
It is advisable to make extra efforts to improve well-being when maintaining sanitary measures by providing appropriate assistance and helping households struggling with increased or acute stress to install positive coping strategies - especially in larger households with children between six and 17 years. Besides, our findings draw attention to the clustering of risk of child and adult violence exposure in lockdown situations as well as to the potential cumulative impact of exposure to violence across the lifespan and across generations. It is key to invest in training healthcare workers and staff at schools to screen for and assess risks of domestic violence development and ongoing or past occurrence in order to detect, refer and follow-up on families at risk.
Mind the gap: Nodes of Ranvier are remodeled by chronic psychosocial stress and neuronal activity
Authors: Hovatta Iiris , Koskinen Maija-Kreetta , Laine Mikaela , Abdollahzadeh Ali , Gigliotta Adrien , Mazzini Giulia , Journée Sarah , Alenius Varpu , Trontti Kalevi , Tohka Jussi , Hyytia Petri , Sierra Alejandra
Published: August 2022

Differential expression of myelin-related genes and changes in myelin thickness have been demonstrated in mice after chronic psychosocial stress, a risk factor for anxiety disorders. To determine whether and how stress affects structural remodeling of nodes of Ranvier, another form of myelin plasticity, we developed a 3D reconstruction analysis of node morphology in C57BL/6NCrl and DBA/2NCrl mice. We identified strain-dependent effects of chronic stress on node morphology, including elongation of paranodes in the medial prefrontal cortex (mPFC) in DBA/2NCrl mice. Furthermore, chronic chemogenetic activation of the ventral hippocampus-to-mPFC pathway resulted in increased risk assessment behavior and shortened paranodes specifically in stimulated axons, providing a direct link between anxiety-like behavior and pathway-specific remodeling of the nodes. Altogether, our data demonstrate 1) genetic regulation of nodal remodeling in stress and 2) axon-specific regulation of paranodes in response to neuronal activity in an anxiety-associated pathway. Nodal remodeling may thus contribute to aberrant circuit function associated with anxiety disorders.
Quantitative EEG Features and Machine Learning Classifiers for Eye-Blink Artifact Detection: A Comparative Study
Authors: Rashida Maliha , Habib Mohammad Ashfak
Published: August 2022

Ocular artifact, namely eye-blink artifact, is an inevitable and one of the most destructive noises of EEG signals. Many solutions of detecting the eye-blink artifact were proposed. Different subsets of EEG features and Machine Learning (ML) classifiers were used for this purpose. But no comprehensive comparison of these features and ML classifiers was presented. This paper presents the comparison of twelve EEG features and five ML classifiers, commonly used in existing studies for the detection of eye-blink artifacts. An EEG dataset, containing 2958 epochs of eye-blink, non-eye-blink, and eye-blink-like (non-eye-blink) EEG activities, is used in this study. The performance of each feature and classifier has been measured using accuracy, precision, recall, and f1-score. Experimental results reveal that scalp topography is the most potential among the selected features in detecting eye-blink artifacts. The best performing classifier is Artificial Neural Network (ANN) among the five classifiers. The combination of scalp topography and ANN classifier performed as the most powerful feature-classifier combination. However, it is expected that the findings of this study will help the future researchers to select appropriate features and classifiers in building eye-blink artifact detection models.
Iopofosine I-131 treatment in late line patients with relapsed/refractory multiple myeloma post anti-BCMA immunotherapy
Authors: Lngcor Jarrod , Callander Natalie , Oliver Kate , Chanan-Khan Asher , Ailawadhi Sikander
Published: August 2022

Over the past decade, significant improvements in survival outcomes have been experienced by multiple myeloma (MM) patients. However, MM remains an incurable disease and patients with triple-class refractory MM have limited treatment options and a dismal prognosis. Chimeric antigen receptor (CAR) T-cell therapy targeting B-cell maturation antigen (BCMA) has transformed the treatment algorithm of relapsed/refractory MM (RRMM), with high overall response rates. Nevertheless, a significant proportion of patients ultimately relapse despite achieving deep remission and show poor outcomes with subsequent treatment post anti-BCMA immunotherapies.1 Iopofosine I-131 (iopofosine) is a first-in-class phospholipid ether radio-conjugate that targets lipid raft microdomains on tumor cells and is internalized. Here we present seven cases of triple class refractory MM patients that relapsed or were refractory to anti-BCMA immunotherapy and treated with iopofosine plus low dose dexamethasone (LoDEX). Patient received a single fractionated cycle of 30mCi/m2 of iopofosine (15 mg/m2 dosed day 1 and day 15) and received LoDEX (40 mg/week for 12 weeks) with an optional second cycle of iopofosine approximately 60 days later. Six of the seven patients achieved the minimum required total administered dose of 60 millicuries (mCi) to be in the evaluable population and 50% achieved a partial response (PR) or better.
Influence of the Electrolyte concentration and amount on the Performance of Textile Electrodes in Electrostimulation: a systematic study
Authors: Euler Luisa , Guo Li , Persson Nils-Krister
Published: August 2022

Background
Textile-based stimulation electrodes are a fast-growing research area. With their advantages including reusability and the possibility for integration into garments, textile electrodes open up new possibilities that are not yet feasible today, e.g. various self-administrated treatments and rehabilitation based on neuromuscular electrical stimulation (NMES) or transcutaneous electrical nerve stimulation (TENS). So far, most research has shown that textile-based stimulation electrodes perform more reliable when wetted with an electrolyte. However, there is no systematic investigation about which type and amount of electrolyte to use.
Methods
In this study, double-layered textile electrodes have been produced by machine knitting with a size of 3x3 cm2. The electrodes were wetted step-wise with a liquid amount from 5 µL up to 320 µL; four levels of sodium chloride (NaCl) concentrations, i.e. 0.9%, 1.5%, 5% and 35%, plus pure deionized water as a reference liquid were chosen. The study analyzed the behavior of the skin-electrode impedance when changing the moisture content and NaCl concentration. In addition, equivalent circuits were modelled for deeper insights into the mechanisms causing an impedance change.
Results
Results showed that the impedance was greatly influenced by the liquid amount with amounts of 5 µL already significantly reducing the impedance compared to dry electrodes, caused by a substantial reduction in resistance. The reactance, on the other hand, was only partly influenced by the liquid amount showing a reduction upon higher liquid amounts only within a range of 5–40 µL. Further, a significant influence on the impedance by the presence of ions was found where the skin-electrode system wetted with saline NaCl solution were showing generally lower impedances than systems wetted with deionized water. However, within this, no remarkable influence of the NaCl concentration could be observed.
Conclusion
Impedance was found to be very sensitive to the moisture content in the system, it is recommended to introduce standardizations for impedance testing of wet textile electrodes with precisely controlled electrolyte volumes and liquid migration properties to make independent studies of textile electrodes more comparable.
Hierarchical Classification of Analog and Digital Modulation Schemes using Higher-Order Statistics and Support Vector Machines
Authors: GOKDOGAN Bengisu YALCINKAYA , CORUK Remziye Busra , KARA Ali , TORA Hakan
Published: August 2022

Automatic Modulation Classification (AMC) algorithms play an important role in various military and civilian applications. There have been numerous AMC algorithms reported in the literature, most of which focus on synthetic signals with a limited number of modulation types having distinctive constellations. The efficient classification of high-order modulation schemes under real propagation effects using models with low complexity is still a challenge. In this paper, employing quadratic SVM, a feature-based (FB) hierarchical classification method is proposed to accurately classify especially higher-order modulation schemes and its performance is investigated using over the air (OTA) collected data. Statistical features, higher-order moments, and higher-order cumulants are employed as features. Then, the performances of some well-known classifiers are evaluated, and the classifier presenting the best performance is employed in the proposed hierarchical classification model. An OTA dataset containing 17 analog and digital modulation schemes is used to evaluate the performance of the proposed classification model. With the proposed hierarchical classification algorithm, a significant improvement has been achieved, especially in higher-order modulation schemes. The overall accuracy with the proposed hierarchical structure is 96% after 5 dB signal-to-noise ratio (SNR) value, approximately a 10% increase is achieved compared to the traditional classification algorithm.
Detailed statistical analysis plan for the Neurological complications in Endoscopic versus Open radial artery harvest (NEO) randomised clinical trial
Authors: Carranza Christian Lildal , Ballegaard Martin , Werner Mads , Hasbak Philip , Kjær Andreas , Kofoed Klaus Fuglsang , Olsen Markus Harboe , Gluud Christian , Jakobsen Janus
Published: August 2022

IntroductionCoronary artery bypass grafting can be conducted using the radial artery as a bypass graft. However, it remains unclear, which harvesting method is superior, i.e. endoscopic or open radial artery, and which site for proximal anastomosis of the radial artery has the greatest benefits?MethodsThe NEO Trial is a single site randomised clinical trial with a 2x2 factorial design. The first comparison assesses endoscopic versus open radial artery harvest with a primary outcome of hand function and secondary outcomes of neurological deficits through clinical exams and neurophysiological studies. The primary outcome is postoperatively hand function at three months. We anticipate a mean difference of 3 points with a standard deviation of 8 points, a power of 90%, and a type I error of 5%, resulting in a required sample size of 300 participants randomised 1:1. Secondary outcomes are neurological deficits (based on nerve conduction measurements, algometry test, von Frey hair test), clinical neurological examination of cutaneous sensibility, and registration of complications in the donor arm (haematoma formation, wound dehiscence, and/or infection). The second comparison assesses two different proximal anastomotic sites, i.e. aorto-radial anastomosis versus mammario-radial anastomosis. The primary outcome is a composite of cerebrovascular events and the secondary outcome is graft patency evaluation by multi-slice computer tomography-scan. These outcomes will be assessed at 1 year postoperatively and the results of this comparison will be exploratory only. Two independent statisticians will follow the present plan and conduct the analyses which will hereafter be fused into a final analysis based on consensus.ConclusionThis detailed analysis plan will increase the validity of the NEO trial results by predefining the statistical analysis in detail. Trial registrationClinicalTrials.gov identifier: NCT01848886. Registered 25th of February 2013, https://clinicaltrials.gov/ct2/show/NCT01848886Danish Ethics committee number: H-3-2012-116Danish Data Protection Agency: 2007-58-0015/jr. n:30-0838
Food-grade Secretory Expression of β-mannanase Mutant in Bacillus subtilis and Its Application for Manoligosaccharides Preparation
Authors: Chen Yun , Gao Weiqiang , Liang Qi , Zhou Xiaolei , Yang Xu , Wu Tianning , Wang Lili , Yang Xiaorui , Zhang Chunxiao
Published: August 2022

β-mannanase is in great demand and has wide application in industrial fields. In order to improve β-mannanase activity, the directed evolution of β-mannanase gene from Bacillus licheniformis KD-1 was carried out by error-prone PCR and expressed in Bacillus subtilis. For the biosafety of β -mannanase application, the B. subtilis food-grade expression system was constructed. Firstly, the d-alanine racemase (dal) gene of the host cell was deleted by CRISPR/CpfⅠ genome editing without scars. Secondly, the corresponding expression vector was constructed by deleting the antibiotics marker genes replaced with dal gene to realize auxotrophic complementation screening. Among mutants, ManBl (I91N/L211I) had the highest enzyme activity of 17601.3 U/mL, and the specific activity was 15554.7 U/mg, which was 3.2 times than that of the wild-type ManBl. Two loci (I91N and L211I) located at outside of the β-mannanase catalytic center influence the enzyme activity at a great degree. The food-grade expressed β-mannanase was applied to degrade konjac glucomannan (KGM) for preparing manoligosaccharides (MOS). The hydrolysis products mainly consisted of mannohexaose, mannotriose, and mannobiose.
Human umbilical cord mesenchymal stem cells conditioned medium exerts anti-tumor effects on KGN cells in a cell density-dependent manner through activation of the Hippo pathway
Authors: Wan Wenjing , Miao Yuyang , Niu Yuwei , Zhu Kunyuan , Ma Yingwan , Pan Menghao , Ma Baohua , Wei Qiang
Published: August 2022

Objectives The conditioned medium from human umbilical cord mesenchymal stem cells (UCMSCs-CM) provides a new cell-free therapy for tumors due to its unique secretome. However, there are many contradictory reports about the effect of UCMSCs-CM on tumor cells. The loss of contact inhibition is a common characteristic of tumor cells. A relationship between the effect of UCMSCs-CM on tumor cells and contact inhibition in tumor cells is rarely concerned. Whether the effect of UCMSCs-CM on tumor cells is affected by cell density? Here, we explored the effect of UCMSCs-CM on KGN cell, which is an ovarian granulosa cell tumors cell line, at low or high density. Materials and Methods Growth curve and CCK8 assay were used to assess cell proliferation and viability. Scratch wound and matrigel invasion assay were implicated to detect cell motility of KGN cells. UCMSCs-CM effects on cell cycle, apoptosis and pathway-related proteins were investigated by flow cytometry, TUNEL assay, western blot and immunofluorescence analysis respectively. Results In growth curve analysis, before KGN cells proliferated into confluence, UCMSCs-CM had no effect on cell proliferation, but once the cells proliferate to contact each other, UCMSCs-CM significantly inhibited proliferation. Meanwhile, when KGN cells were implanted at high density, UCMSCs-CM could induce cell cycle arrest at G1 phase, inhibit cell migration, invasion and promote apoptosis. However, it had no similar effect on KGN cells implanted at low density. In mechanism, the UCMSCs-CM treatment activated the Hippo pathway when KGN cells were implanted at high density. Consistently, the MST1/2 inhibitor, XMU-MP-1, inhibited the activation of the Hippo pathway induced by UCMSCs-CM treatment and accordingly declined the anti-tumor effect of UCMSC-CM on KGN cells. Conclusion The effect of UCMSCs-CM on tumor cells is affected by cell density. UCMSCs-CM exerted anti-tumor effect on KGN cells by activating Hippo pathway to restore contact inhibition. Our results suggest that UCMSCs-CM is a promising therapeutic candidate for GCTs treatment.
Experience of Research Ethics Committees in Africa during the COVID-19 Pandemic
Authors: Woldeamanuel Yimtubezinash , Abay Solomon M. , Ashuro Akililu Alemu , Berhe Derbew Fikadu , Degafa Tseday Tilahun , Munung Nchangwi Syntia , Tangwa Godfrey B. , Karbwang Juntra , Abdissa Alemseged
Published: August 2022

Background and objective
: Globally, COVID-19 has caused a number of challenges including the functioning of research ethics committees (RECs) with the impact being expected to be more pronounced in resource-limited countries. The objective of this study was to describe RECs' functions and challenges experienced during the pandemic in Africa.
Method
A cross-sectional study covering Anglophone and Francophone countries in Africa was done. Data was collected using an online Google form questionnaire. The link to the form was sent to REC chairs and secretaries to fill in online. Descriptive data analysis was done using Microsoft Excel and SPSS version 25.
Result
A total of 98 study participants (50 members and 48 chairs) responded from 16 African countries. The mean (standard deviation) age of REC members was 47 (12) and over half of them, 27 (54%) were female. Most REC members and chairs were physicians, while 48% of RECs were affiliated with academic institutes. Ninety percent of REC chairs reported that their REC was accredited; however, only three had recognition by Strategic Initiative for Developing Capacity in Ethics Review (SIDCER). RECs reported reviewing COVID-19 related protocols. In 2019, chairs reported RECs reviewing 5,860 protocols with a 13% increment in 2020. During the COVID-19 pandemic, there was an increment in protocol amendment (79%), deviation (29%), and early protocol termination (25%). Most (96%) RECs followed COVID-19 prevention institutional policies including limiting face-to-face meetings and shifting to virtual platforms. RECs challenges in reviewing COVID-19 related proposals were issues related to risk/benefit, scientific design, and informed consent.
Conclusion
The COVID-19 pandemic has impacted the functions of RECs in Africa, both in the increase in the volume of proposals for review and presenting new ethical challenges including in risk-benefit analysis. There is a need to strengthen RECs in the region through different mechanisms, by building their capacity through initiatives like the SIDCER recognition program. To strengthen African RECs in a sustainable manner, some of the interventions could be establishing National and regional REC databases, and putting in place continuous training opportunities preferably through an online platform.
The Efficiency of Focused Assessment with Sonography for Trauma in Pediatric Patients with Blunt Torso Trauma
Authors: inci Ozlem , Altuncı Yusuf Ali , Can Ozge , Akarca Funda Karbek , Ersel Murat
Published: August 2022

Background and importanceFocused Assessment with Sonography for Trauma (FAST) has attracted attention for its use in the detection of intraabdominal pathology. However, Computed Tomography (CT) remains the gold standard for the assessment of blunt torso trauma. ObjectiveThe study examines the effectiveness of FAST both in the detection of intraabdominal pathology in pediatric patients (< 19 years) and in the assessment of the need for CT for further examination. DesignThe study was designed as a retrospective observational investigation of diagnostic value.SettingThe pediatric patients who were admitted to the emergency department with blunt torso trauma between January 2013 and October 2016 were included in the study. The sample of the study comprised 255 patients who met the inclusion criteria.Outcome measures and analysisThe demographic data, vital findings, trauma mechanism, physical examination findings, the presence of a concomitant trauma, laboratory findings, CT scans of the thorax and abdomen, FAST findings, and patient outcomes were recorded. The Chi-square test and Fisher’s exact test were used for comparisons. A logistic regression model was developed to determine the variables that independently affect the agreement between FAST and CT.Main resultsThe comparison of FAST and CT revealed a poor agreement in pediatric patients with blunt torso trauma. The agreement was negatively affected by the severity of trauma and the presence of concomitant trauma. The error rate of FAST increased by five-fold especially in the presence of concomitant thorax trauma. However, FAST had a good negative likelihood ratio.ConclusionFAST was determined to yield accurate results when used in stable patients, thus revealing it as an appropriate tool for the initial examination of stable pediatric patients with blunt torso trauma. For unstable patients, however, a negative or positive FAST examination should not guide the decision to use CT and CT should remain a standard tool for further examination. FAST should not be regarded as an equivalent or complementary tool to CT. It is, instead, a noteworthy negative predictor in pediatric patients. A positive FAST result can serve as a predictor of the need for operation and hospitalization in multiple trauma patients.
Current incident reporting and learning systems yield unreliable information on patient safetyIncident reporting reliability
Authors: Plukka Mari , Rauhala Auvo , Fagerström Lisbeth , Ikonen Tuija
Published: August 2022

BackgroundIncident reporting systems are being implemented throughout the world to record safety incidents in healthcare. The quality of the recording and analysis of reporting systems is important for the development of safety promotion measures. MethodsTo assess the reliability of incident reporting ratings collected in a hospital setting, a three-level interrater comparison was undertaken. The routine ratings of the frontline event handlers responsible for evaluating safety incident reports (n=495) were compared with the parallel ratings of two trained patient safety coordinators. The two patient safety coordinators then each separately reviewed about half of the 495 reports, followed by reclassification of a random sample (a random data subset of 60 reports) previously reclassified by the other coordinator during the first reclassification. The following seven patient safety variables were included: nature of the incident, type of incident, patient impact, treating unit impact, circumstances and contributory factors, immediate actions taken, risk category. Interrater agreement was tested with kappa, weighted kappa or iota.ResultsFor the seven variables examined, event handlers had an average of 1.36 missing answers, patient safety coordinators 0.32. For the first interrater comparison, the average change between the three ordinal scale variables for all variables together was towards more serious in 29 % (95%CI: 27%, 32%) and towards less serious in 2 % (95%CI: 0%, 5%) of incidents. The net change for the first interrater comparison was 27% (95%CI: 25%, 30%) towards a more serious incident. The average selection of several categories, when allowed, increased from 7 % (95%CI: 6%, 8%) to 33% (95%CI: 31%, 35%). For all three paired interrater comparisons, the average interrater agreements were in the range of 0.44 to 0.53 and considered moderate. While patient safety coordinators should in theory represent a ‘golden standard’, the coordinator interrater agreement seen in this study was moderate. ConclusionConsensus at national level on how to classify high-risk incidents is needed to develop incident reporting reliability. Also, continuous training in common practices, terminology and rating systems should be given more attention. Having a patient safety coordinator reclassify incident reports can improve reporting accuracy and thereby corrective actions and learning.
Epidemiological and hematological profile of traumatic spinal cord injury: a retrospective study
Authors: Li Fang , Wei Changkun , Huo Su , Song Weiqun
Published: August 2022

Study design: A retrospective hospital-based study.Objective: To describe the epidemiological features and identify hematological indicators with prognostic value for function of traumatic spinal cord injury (TSCI) in Beijing, China.Setting: Xuanwu Hospital of Capital Medical University, Beijing.Methods: Routine blood and clinical data of TSCI patients who admitted to Xuanwu Hospital of Capital Medical University from 2015 to 2021 were collected for detailed investigation.Results: In all, 129 cases were identified. The most commonly affected age group was 46-60 years, and male-to-female ratio was 2.5:1. The leading cause was low fall (50.4%), followed by transport (25.6%). The most common injury site was the cervical spinal cord, especially C5, accounting for 86.0%. The proportion of TSCI patients receiving rehabilitation treatment after acute management was 27.2%. In addition, hemoglobin (Hb) concentrations in TSCI patients with increased Barthel index (BI) scores were significantly higher than those without increased BI scores (P＜0.05). Conclusion: Prevention strategies for TSCI should mainly target 46-60 age group, males and low fall. The results of this study will serve as a basis for further studies on TSCI, at least in Beijing. The preventive programs should be designed according to the injury characteristics. Additionally, higher Hb concentration in peripheral blood is closely related to the improvement of activities of daily living (ADL) in TSCI patients, but further detailed research is urgently needed.
Patient-Reported Outcome Measures compared to Clinician Reported Outcomes regarding incontinence and erectile dysfunction in localized prostate carcinoma after Robot Assisted Radical Prostatectomy: impact on management
Authors: Tillier CN , Boekhout AH , Veerman H , Wollersheim BM , Groen PAM , Poel HG van der , de Poll-Franse LV van
Published: August 2022

Purpose/ Background: To examine whether a discrepancy between patient reported outcomes (PROs) and clinician reported outcomes (CROs) impacts the management of urinary incontinence (UI) and erectile dysfunction (ED) after robot assisted radical prostatectomy (RARP). Methods: Up to 1 year after RARP, UI and ED recovery of 312 men with localized and locally advanced prostate cancer were assessed using the International Consultation Incontinence Questionnaire Short Form (ICIQ-SF) and the International Index of Erectile Function (IIEF-EF) and CROs by interview. Discrepancies between PROs and CROs were studied in light of treatment offered and management.Results: The ICIQ-SF Score matched with CROs in all sum score categories except in ICIQ sum score 6-12; here the UI was underreported by clinicians in 58% and 59% of patients at 8 and 12 months (p<.001). Furthermore, at 8 and 12 months postoperatively, clinicians underreported UI in 29% and 23% of patients with ICIQ score 13-18 (p<.001). The clinician significantly over-reported the recovery of erectile function (“normal erection”) (p<.001), especially in men with IIEF-EF sum score 6-16. Independently of ICIQ-SF/IIEF-EF scores, discrepancy between PROs and CROs did not affect rate of health care offered to patients. Conclusions: This is to our knowledge the first study that compared the PROs with clinician reported functional outcomes and the impact of discrepancies on the management of side effects of RARP in prostate cancer. Observed discrepancies between the PROs and CROs did not affect offered management and counseling of UI and ED.