bluuebunny/crossref_metadata_2025 huggingface dataset:
Estimating Formation Tops While Drilling Using Rate of Penetration (ROP) and Mechanical Specific Energy (MSE)
Authors: Alshahrani Saeed , Ayadiuno Chris
Published: October 2023

Accurate determination of formation tops while drilling is a critical part of exploration geology workflow. Operational decisions on coring, wireline logging, casing and final well depth largely depend on it. One of the commonly used methods for picking formation tops while drilling is to correlate rate of penetration (ROP) of the new well to wireline logs from offset wells where there is no logging while drilling (LWD) data. Placing formation tops based on ROP only can result in picking the wrong formation tops. To improve the workflow and outcome, this paper proposes the combination of ROP and Mechanical Specific Energy (MSE) for estimating formation tops while drilling. MSE is a measure of energy required to crush or drill through a unit volume of rock. Because MSE is related to rock strength, it can be correlated to changes in lithofacies and formation tops.

Three key steps necessary for utilizing mechanical specific energy to estimate formation tops. The first step involves selection of input drilling data relevant to the applicable MSE equation. There are several empirical equations in the literature which can be used for estimating MSE. Input data are ROP, Weight on Bit (WOB), Bit Size (BS), Rotation Per Minute (RPM), and Torque (TORQ) from both the offset wells and the new well. Second, it is necessary to utilize predetermined empirical equation to estimate MSE. Third, correlate MSE and ROP from the new well to MSE, ROP and wireline logs from offset wells (where available) in order to determine formation tops in the new well. Application of the proposed workflow to two wells shows 1) distinct bed boundaries, which agree with formation tops picked using wireline logs; (2) that including MSE increases confidence and reliability of the data and makes it easy to identify the different formation boundaries based on the observed features of both MSE and ROP in the new well; and (3) that MSE variations are sensitive to formation strength, which may indicate rock mechanical changes and formation heterogeneity.

This paper presents an alternative method of picking formation tops using MSE and ROP while drilling. The preliminary results based on the two test wells showed over 95% match with those picked using wireline logs of the same new well. As a result, this workflow enhances the ability of geoscientists to correlate subsurface geological features, reduces the uncertainty associated with picking formation tops, casing and coring depths. Furthermore, it improves the confidence in the result of picking formation tops, enhances quality of operational decisions and reduces non-productive time (NPT) and well-cost.
A Novel Surrogate Model for Reservoir Simulations Using Fourier Neural Operators
Authors: Kazemi Mohammad , Takbiri-Borujeni Ali , Nouroizeh Hossein , Kazemi Arefeh , Takbiri Sam , Wallrich Clayton
Published: October 2023

This paper presents a novel approach using deep learning to address the computational challenges associated with direct numerical simulation (DNS) in reservoir management for oil and gas recovery optimization. DNS involves solving partial differential equations for millions of numerical grids, making it time-consuming and computationally expensive, especially when multiple DNS runs are required for uncertainty quantification. The proposed approach utilizes a deep learning model with a new neural operator that parameterizes the integral kernel directly in Fourier space, enabling fast and efficient predictions. By leveraging this approach, the heavy lifting of multiple DNS processes is eliminated, reducing computational time from hours to seconds. The methodology is applied to a two-dimensional reservoir use case, demonstrating its effectiveness in accurately predicting simulation results at a grid level with less than 10 percent error. This approach offers significant potential in accelerating reservoir simulation processes and optimizing oil and gas recovery strategies.
Characterization of Two-phase Slug Flow using Distributed Acoustic Sensing in Horizontal Pipes
Authors: Ali S. , Jin G. , Fan Y.
Published: October 2023

This article discusses the use of Distributed Acoustic Sensing (DAS) to monitor and characterize two-phase slug flow in horizontal pipes. This technology utilizes a regular telecommunication fiber connected to a DAS interrogator to detect flow signals and provide substantial insights into flow characterization and quantification. The capabilities of the DAS are highlighted through a series of experimental tests using various rates of two-phase liquid and gas fluids.

The experiments were conducted in a multiphase flow loop consisting of a transparent polyvinyl chloride (PVC) horizontal test section measuring 14 m. long and 5 cm. inner diameter. A fiber cable was wrapped helically on two 35 cm. long sections, around 61 cm apart, with 11 loops per cm on each section. Mineral oil, tap water, and compressed air were used as the testing fluids. The oil phase velocity varied from 0.2 to 0.8 m/s, while the gas phase varied from 19 to 95 LPM. The facility was also equipped with a high-speed camera and an Electrical Capacitance Volumetric Tomograph (ECVT) system for cross-validating purposes.

New low-frequency strain-rate analysis of the DAS signal demonstrates its capabilities of quantifying two-phase slug flow characteristic parameters, including the slug frequency, slug body length, slug translational velocity, the slug unit, and the liquid film region lengths. The results were compared with the data obtained from the high-speed camera, located right next to the wrapped fiber section, and ECVT, located after the second wrapped section. The three measurements show good matches for all tested flowing conditions. The results will shed light on the production prediction and profiling for slug flow in wellbores or surface pipeline systems.

Compared to other sensors that can also characterize slug flow, such as optical or conductivity/capacitance sensors, DAS technology has the advantages of real-time and continuous measurement over long distances. It can also be applied in harsh environments such as in downhole wellbore conditions where other sensors may not withstand. It opens the doors of production profiling in wellbore/pipeline over long distances which cannot be realized by other point sensors. The cost is relatively low in the field application compared to other point sensors, especially in conditions where measurements are required at multiple locations, with the fact that fiber cable is much cheaper compared to other sensors.

For the first time, this study shows in detail the capability of DAS in characterizing two-phase slug flow in horizontal pipes, and its potential for production profiling in horizontal wells and surface pipeline systems. New insights on the low-frequency DAS signal are discussed along with the physical interpretation of the slug flow dynamics. The new analysis will be beneficial to the petroleum industry in advancing production profiling technologies, production process optimization, and operation safety management.
A Comparative Study of Deep Learning Models for Fracture and Pore Space Segmentation in Synthetic Fractured Digital Rocks
Authors: Wang Hongsheng , Guo Ruichang , Leng Jianqiao , Hosseini Seyyed A. , Fan Ming
Published: October 2023

This study focuses on the comparative study of deep learning (DL) models for pore space and discrete fracture networks (DFNs) segmentation in synthetic fractured digital rocks, specifically targeting low-permeability rock formations, such as shale and tight sandstones. Accurate characterization of pore space and DFNs is critical for subsequent property analysis and fluid flow modeling. Four DL models, SegNet, U-Net, U-Net-wide, and nested U-Net (i.e., U-Net++), were trained, validated, and tested using synthetic datasets, including input and label image pairs with varying properties. The model performance was assessed regarding pixel-wise metrics, including the F1 score and pixel-wise difference maps. In addition, the physics-based metrics were considered for further analysis, including sample porosity and absolute permeability. Particularly, We first simulated the permeability of porous media containing only pore space and then simulated the permeability of porous media with DFNs added. The difference between these two values is used to quantify the connectivity of segmented DFNs, which is an important parameter for low-permeability rocks. The pixel-wise metrics showed that the nested U-Net model outperformed the rest of the DL models in pore space and DFNs segmentation, with the SegNet model exhibiting the second-best performance. Particularly, nested U-Net enhanced segmentation accuracy for challenging boundary pixels affected by partial volume effects. The U-Net-wide model achieved improved accuracy compared to the U-Net model, which indicated the influence of parameter numbers. Similarly, nested U-Net has the closest match to the ground truth of physics-based metrics, including the porosity of pore space and DFNs, and the permeability difference quantifying the connectivity of DFNs. The findings highlight the effectiveness of DL models, especially the U-Net++ model with nested architecture and redesigned skip connections, in accurately segmenting pore spaces and DFNs, which are crucial for pore-scale fluid flow and transport simulation in low-permeability rocks.
Implementation and Evaluation of Digital Sliding Automation for Remote Directional Drilling Operations
Authors: Forrest D. , Neufeldt A. , Fernandes A.
Published: October 2023

Slide drilling with a bent housing downhole motor is the most widely utilized method of directional control for unconventional reservoirs in North America. There are many challenges involved with consistent directional control using this method, given the increased directional work for more complex well trajectories. Challenges include managing reactive torque generated at the bit, sliding through lithology transitions, and adapting to the ever-changing relationship between differential pressure and tool orientation. Additionally, since sliding is primarily a human managed process, performance can vary substantially between directional drillers for the same rig and well. Digitally automated sliding provides consistency, accuracy, improved rate of penetration, and better management of toolface through challenging transitions. Additionally, digitally automated sliding easily enables fully remote directional drilling operations.

This paper outlines the implementation of fully remote directional operations using a digitally automated sliding application running on the rig's process control system. The software application uses auto-populated fields for target toolface and slide length from an off-site directional driller, which are accepted by the driller on location. The software application uses machine learning to achieve the correct reactive torque and differential pressure for orienting toolface both while tagging bottom and while sliding. Once active, the software takes control of the top drive and draw works to orient toolface and maintain minimal toolface error while increasing ROP.

Thorough analysis of human versus digital automation will be presented across multiple well pads in the same field on a Super Triple 1500HP AC rig. Overall performance will be evaluated by comparing toolface error while sliding as well as sliding ROP. This paper demonstrates that sliding automation has achieved a 50% improvement in sliding ROP while reducing toolface error by 30% over manual sliding in the same section. Human factors influencing the implementation of sliding automation will also be discussed. Final analysis will focus on the broader performance gains such as improvements in effective motor yields and sliding intervals needed to achieve directional requirements.

The intention of this paper is to provide a robust analysis of the benefits that digital sliding automation can provide. By analyzing a large dataset to attenuate the effects of well-to-well variables, results are more representative of automation's true value. There is a significant focus on analyzing aspects of the operation that are difficult to quantify, such as automation's effect on motor yields. This paper describes a sliding technology that not only utilizes differential pressure for toolface control, but also incorporates machine learning to automatically learn from previous slides for better optimization of both the tagging bottom and sliding processes going forward.
DNA Tracer Application in a Waterflood Study in Edmisson Field: A Case History
Authors: Asadi M. , Blair T. , Ryan J.
Published: October 2023

This paper presents and discusses data on the application of DNA tracers to a waterflood project in Edmisson Clearfork field in Permian Basin, Tx. The field is divided into two sections, West and East. The West section includes five injection wells, fifteen producers and the East section includes two injection wells and nine producers. To fully understand the flow path within both sections, seven unique DNA tracers were selected and injected. In addition, it was desirable to accurately determine water breakthrough through each production well and to evaluate heterogeneity of the formation between the injection and production wells. Furthermore, identification of high and low permeability zones within the reservoir was identified. Reservoir properties such as drainage area, porosity, water saturation, connate water saturation and water injection rate per well along with the minimum detection limit of DNA tracers were used to calculate the amount of DNA tracers needed to inject in each injection well. A robust sampling schedule was used to make sure an early detection of tracer(s) at each production well. A selected number of samples were used for analyses of tracers. Other samples were kept for future analyses as needed depending on tracer response curve between each injection well and producer.
Restoring Well Integrity on a Damaged Wellhead: Lessons Learned in an Unconventional Intervention
Authors: Baig Umair Ahmed , Al Mohammad Mohammad , Khamis Al Samahi Musabbeh , Abu Aisha Mohamed , Abdulla Al Mutawa Ahmed , Levison Mwansa Peter
Published: October 2023

While performing a mast-up rig move on a recently completed well, the spreader beam of the substructure hit the X-mass Tree (Christmas tree), which in turn caused the X-mass tree and the wellhead to tilt by 21 degrees. Due to the visible damage to the wellhead and tree, as well as the unseen damage to all the tubulars downhole, an unconventional approach was required to intervene and remediate this well so that the operator could proceed with either restoring the well or going for a Plug and Abandon (P&A) option.

The primary stage of operations was to assess the damage inflicted, which revealed that the crossover that connects the casing hanger to the 13-3/8″ casing, had been bent due to the impact. It was imperative to make the Christmas tree and Wellhead assembly vertical before conducting any operations. The assembly was anchored on the traveling block, and then a horizontal force was applied to restore the wellhead to a vertical position. To ensure tubing accessibility, a gauge cutter run was performed; however, it could not pass through the bent area, which was just below the tubing hanger.

To perform any remedial/intervention operations the first and foremost step was to fabricate a support structure to be able to bear the axial weight of Blow Out Preventers (BOP) since the wellhead was already damaged. The tubing was recovered by mechanically backing it off and pulling it out of hole. While pulling out the tubing to surface, it was discovered that the tubing was damaged as well due to the impact. The casing was then assessed for any damage, and the Original Equipment Manufacturer (OEM) were engaged to determine the mechanical properties of the casing for any further production from this well. A dedicated bit trip followed by a Polish mill was performed to check for any damage caused to the 7″ casing caused by the incident. Complete casing integrity was restored, and a new completion was installed to bring the well back online.

The innovative ideas used to restore the well's integrity and return it to production could serve as a case study for future wells that face the unexpected scenario of the x-mas tree or wellhead tilting and bending the casing and tubing strings. Rather than abandoning the well, the lesson learned in this case can be applied to recover such wells and produce from them.
Improved Well Integrity Using a Novel Fluid Technology to Overcome Large Fracture Networks and Permeable Formations
Authors: Shine J. M. , Sowailem A. , Gbemiga I. , Bermudez F.
Published: October 2023

It is common to hear of lost circulation and well integrity together when discussing well construction risks. Normally, it is difficult to achieve well integrity unless curing losses prior to or during cement placement allowing achievement of the isolation requirements. Losses, especially in carbonate formations, can result from fracture networks or naturally permeable formations which can be challenging to consolidate and restore the wellbore circulation. The deployment of a novel fluid technology shows success across challenging lost circulation zones where similar technologies show unfavorable results. The paper discusses the technology evolution, performance, and results from field evaluation.
Repurposing of Hydrocarbon Pipelines for CO2 Injection in CCS Project – Can it be Done?
Authors: Lam C. M. , Kuanji J. J.
Published: October 2023

The company is embarking on Carbon Capture and Storage (CCS) by injecting CO2 into depleted offshore gas reservoir located in the east coast of the Malaysia Peninsular, as part of the CO2 Decarbonization to achieve Net Zero Carbon Emissions (NZCE) by 2050. One of the main scopes is to evaluate the technical feasibility and viability to repurpose the existing hydrocarbon pipelines for CO2 transportation. This paper aims to share our experiences and the challenges we faced to determine the possibility of utilizing existing hydrocarbon pipelines for CO2 transportation.

The pipelines have been in operation for 41 years and have exceeded their design life. This necessitates the Asset Life Extension Study (ALES) to ascertain whether these pipelines can still be operated for another 20 years based on the CCS CO2 injection design life. Following the outcome of the ALES study, inspection and maintenance scopes have been identified to be conducted to ascertain pipeline integrity. Once these have been done, the pipelines will undergo technical assessments and evaluations to establish the integrity, criteria, and operating envelope for the purpose of CO2 transportation for injection.

Through various integrated multi-disciplinary workshops held internally utilizing the company's subject matter experts, the followings detail out of the key technical considerations to repurpose the pipelines for CO2 transportation: (1) Pipeline integrity assessment, taking into account current and future operating conditions, as well as Running Ductile Fracture and propagation control. (2) Corrosion assessment and corrosion inhibitor in high CO2 environment. (3) Non-metallic elastomer requalification. (4) Hydraulic analysis including pipeline capacity, phase behavior, and CO2 quality. (5) Process flow assurance study and thermodynamics modeling. (6) Safety evaluation workshop addressing the safety requirements due to CO2 transport.

All studies are taking place concurrently and pending completion, with the aim of establishing the Fitness for Service (FFS) for these repurpose pipelines. CCS CO2 injection project is CAPEX intensive, therefore the possibility of repurposing existing hydrocarbon pipelines for CO2 transportation offers an attractive opportunity to offset some of the high investment cost required.
Key Technologies and Solutions to Manage Risks and Overcome the Deepwater Challenges in an Integrated Services Project in the Gulf of Mexico
Authors: Davila Andres Nunez , Lopez Juan Ramon , Rossi Lucas , Lin Emily , Giam David , Widhihabsari Martha , Hill Jesse , Jackson Richard , Basso Miguel , Jaimes Juan Pablo , Bouguetta Mario
Published: October 2023

The deepwater environment is traditionally characterized by high operating costs, making any operational savings extremely valuable when facilitating project development and execution. In a highly volatile oil price environment and while under a long-term commercial relationship, a new strategy was implemented to achieve performance optimization and time reduction. This strategy aimed to attain high efficiency and consistency through the application of an integrated services performance and reward model. The core objective of integrated services projects is to generate synergies for further project optimization, while the goal of a reward model is to promote the utilization of diverse technologies to manage risks and minimize the occurrence of undesirable events. In this paper we aim to describe how various technologies and digital solutions can be integrated to serve risk management endeavors, optimize performance, and meet project-specific needs.

The integrated services performance and reward model was designed based on three components: project success criteria, historical nonproductive time (NPT), and key performance indicators (KPIs). Major technologies were evaluated and selected in accordance with the project requirements. Digital solutions were implemented to establish a performance baseline, assist in defining the planned time, and assess project-related risks. Critical tasks involved not only planning but also monitoring the results and comparing them to the KPIs, as well as identifying instances of invisible lost time. In the Gulf of Mexico, characterized by narrow operating windows and frequent lost circulation events, continuous monitoring and control of drilling fluid properties are mandatory, supported by the implementation of digital and automated solutions. In addition, key technologies were introduced for formation characterization and further area development.
Geopolymer for Oilfield Application: Scaling Up Laboratory Test to Yard Test
Authors: Sazali Y. A. , Medvedev A. , Yakovlev, A. , Riyanto L. , Ebining M. S. , Rahman S. H. , Zulkarnain N. N. , Kumar A. K. , Lau C. H.
Published: October 2023

The present paper describes applicability of geopolymers to oilfield use. As a completely new system in oilfield, one of the main concerns about geopolymer was compatibility with oilfield equipment. It is known that geopolymer system differs from a conventional cement by a composition of base fluid and a mixing order which leads to a question of capability of existing cementing equipment to handle the geopolymer slurries. In order to validate mixability and pumpability of geopolymer slurry, a yard test had been conducted in order to test geopolymer formulations with two densities, 15 and 16.5 pgg. The yard test proved that the geopolymer system could be mixed and pumped using conventional equipment in the batch mixing as well as in the on-the-fly pumping regimes. During the yard test the geopolymer formulations were pumped with a rate up to 6 bbl/min. Results showed that special attention should be paid to a base fluid preparation and HSE aspects of the mixing and pumping process. The articles discuss practical recommendation about geopolymer preparation and pumping.

For the first time it was demonstrated that geopolymer systems could be mixed and pumped using conventional cementing equipment. All mixed geopolymer slurries tested according to the API RP 10B standard and demonstrated acceptable properties, including rheology, thickening time, compressive strength and fluid loss. In addition to that the paper suggests the draft of the quality control procedure for geopolymers used in oilfield.
Large Language Models (LLMs) for Natural Language Processing (NLP) of Oil and Gas Drilling Data
Authors: Kumar Prateek , Kathuria Sanjay
Published: October 2023

In the oil and gas industry, drilling activities spawn substantial volumes of unstructured textual data. The examination and interpretation of these data pose significant challenges. This research exploits the emerging capabilities of large language models (LLMs) with over 100 billion parameters to extract actionable insights from raw drilling data. Through fine-tuning methodologies and the use of various prompt engineering strategies, we addressed several text downstream tasks, including summarization, classification, entity recognition, and information extraction. This study delves into our methods, findings, and the novel application of LLMs for efficient and precise analysis of drilling data.
Pushing the Limits of Multi Port Open Hole Completions to Maximize Hydraulic Fractures
Authors: Rahim Zillur , Watson Mark , Wilson Stuart
Published: October 2023

For the optimization of hydrocarbon recovery, tight and moderately tight gas reservoirs generally require hydraulic fracturing to connect the reservoir with the well and ascertain long-term sustained production. The open hole multistage fracturing completions (OHMSF) technology has become a game-changer to enhance production and optimize fracture placement. The open-hole sections allow the entire reservoir section to stay in contact with the wellbore at all times, while different segments of the completion assembly are equipped with isolation packers and fracturing ports and nozzles through which independent hydraulic fractures are initiated in stages and propagated in the reservoir. Throughout the years, OHMSF completion assemblies have gone through important upgrades and customization as functions of reservoir properties and well trajectories, and have proven to be one of the most cost-effective, efficient, and result-oriented technologies applied in the oil and gas industry.
Identification of Potential Aquifer Recharge Sites for CO2 Storage in the Sinu-San Jacinto Basin in Colombia
Authors: Rojas-Barrientos Juan-Camilo
Published: October 2023

The leakage of carbon dioxide in geological storage sites is one of the main risks in carbon capture and storage (CCS) projects. Potential CCS sites in the subsurface rely on hydraulic barriers to prevent migration of stored CO2. In addition, CCS sites rely on rocks that can form stable carbonates saturated with water and in the presence of captured CO2, ensuring long-term storage. Aquifer recharge zones are areas on the Earth's surface through which water infiltrates into the subsurface. The flow of water from the surface to the subsurface helps maintain pressure in the aquifer, acting as a hydraulic barrier between the recharge zone and a potential CO2 storage site. This article aims to identify possible CO2 storage sites in aquifer recharge zones in the Sinu-San Jacinto sedimentary basin in Colombia. Potential CO2 storage zones were identified through spatial processing in a geographic information system (GIS), using a digital elevation model (DEM), available geological mapping, and land cover information. The results were compared with the aquifer recharge zone map of Colombia to identify potential CO2 storage sites.
Minimal catalytic assemblies can demonstrate periodic (dis)assembly cycles in a closed system utilizing feedback loops
Authors: Reja Antara , Jha Sangam , Pal Sumit , Bal Subhajit , Das Dibyendu
Published: October 2023

The light-dark cycles created from Earth’s rotation helped in the emergence of extant cellular life that integrates evolved oscillatory networks to control circadian rhythms, cell division, metabolism and so forth. Out of equilibrium networks of organic chemical reactions with dynamic self-assembled structures that emerged from Darwin’s nutrient-rich warm pond played crucial roles in spawning the protolife under a fluctuating environmental condition. Construction of chemical networks from simple chemicals that can display emergent network dynamics can contribute to our understanding of complex behaviours from simple organic reactions. Here we have designed single amino acid/dipeptide based systems that could demonstrate multiple periodic changes of (dis) assembly under non-equilibrium conditions in closed system, importantly in the absence of evolved biocatalysts. The two-component based building block exploited pH driven non-covalent assembly and time-delayed accelerated catalysis from self-assembled state to install orthogonal feedback loops with a single batch of reactants. Modifications of these autonomous systems from purely synthetic molecules can enable the design of exceptional life-like materials and evolving systems with acute spatiotemporal control of properties.
Genetically modified MSCs into neuraland endothelial cell-like cells inducedby a branched peptide amphiphile hydrogel
Authors: Yin Peiyi , Li Yixiu , Zhou Tiantian , Wu Kai , song yulin
Published: October 2023

Background： Spinal cord injury (SCI) remain one of the great clinical challenges because of their considerable long-term disability potential. In this study, A branched amphiphilic peptide (B-PA) segments were constructed and self-assembled into hydrogels to support bone marrow derived mesenchymal stromal cells (BMSCs) encoding Recombinant Rat VEGF165（VEGF165）, neurotrophins-3(NT-3)and angiopoietin-1(ANG-1) genes. In addition, B-PAS promoted the transdifferentiation of BMSCs into nerve and vascular endothelial cells.
Methods：Self-assembly of b-PA into a nanofiber hydrogel was triggered by the culture medium and analysed by transmission electron microscopy (TEM). Rat BMSCs were cultivated using the differential adhesion method and assessed by flow cytometry. Cells were inoculated into the hydrogel and investigated using calcein-AM/PI, CCK-8, and cell adhesion assays. Cells transfected with adenoviral vectors of biocarrier (Adv-Bic) and adenoviral vectors of NT-3 gene (AdvNT-3) were cultured for 7 days and evaluated by immunofluorescence and real time quantitative reverse transcription-PCR.
Results：The molecular weight and purity of b-PA were 2191.72 and >95%, respectively. Self-assembled nanofibers had a diameter of 5-8 nm and a length ranging from hundreds of nanometres to micrometres. The resulting CD29+/44+ cells could differentiate into osteoblasts and fat cells, and the hydrogel supported cell growth, proliferation and adhesion. Cells in the hydrogel overexpressed VEGF165, NT-3 and Ang-1, and NSE and Nestin markers of CD31+/34+ cells were also abundant.
Conclusions： The hydrogel has potential as a tissue engineering scaffold with good cytocompatibility, and can induce genetically modified BMSCs to transdifferentiate into neural and endothelial cell (EC)-like cells. The article have selected preprint on the research platform, this article has been assigned a DOI, The DOI is:10.21203/rs.3.rs-1822746/v1.
Safety and Efficacy of Dexmedetomidine Nasal Spray for Pre-anaesthetic Sedation in Children: A Randomised, Double-Blinded, and Placebo-Controlled Trial
Authors: Gao Jia , Wang Fang , Wang Xiaoling , Zou Xiaohua , Liu Hua-cheng , Song Xingrong , Chai Xiaoqing , Jiang Rong , Zhao Ping , Zhang Jiaqiang , Wang Sai-ying , Ma Haichun , Zhao Zhibin , Wang Quanren , Zhou Na , Bai Jianling , Zhang Jianmin
Published: October 2023

Background
Off-label intranasal administration of dexmedetomidine injection has been widely applied in the pediatric sedation setting. We developed a dexmedetomidine nasal spray for pediatric pre-anaesthetic sedation.
Objective
To evaluate the pre-anaesthetic sedation efficacy and safety of the dexmedetomidine nasal spray in children.
Methods
Subjects between 2 and 6 years who were to undergo selective surgery were randomized to receive dexmedetomidine nasal spray or placebo in a 2:1 ratio. The dosage was 30 µg or 50 µg based on the body weight. The primary outcome measure was the proportion of subjects who achieved successful child-parent separation and were with Ramsay scale ≥ 3 within 45 min after administration. Secondary outcome measures included the proportions of subjects reaching successful parental separation, with Ramsay scale ≥ 3 at least once and UMSS ≥ 2 at least once within 45 min after administration, and the time from administration to the first time reaching Ramsay scale ≥ 3 and UMSS ≥ 2,. Safety was monitored via the assessments of adverse events, blood pressure, heart rate, respiratory rate and blood oxygen saturation.
Results
The proportion of subjects achieving successful parental separation and with Ramsay scale ≥ 3 within 45 min after administration was significantly higher in the dexmedetomidine group (94.4%) vs the placebo group (32.0%) (P < 0.0001). As compared with placebo, dexmedetomidine treatment led to more subjects achieving Ramsay scale ≥ 3 or UMSS ≥ 2, and shorter time to reach successful parental separation, Ramsay scale ≥ 3 and UMSS ≥ 2 (all P < 0.0001). Adverse events were reported in 90.7% and 84.0% of subjects in the dexmedetomidine and placebo groups, respectively, and all the events were mild or moderate in severity.
Conclusions
Dexmedetomidine nasal spray presented effective pre-anaesthetic sedation in children with a favorable safety profile.
Trial registration:
Clinicaltrials.gov, identifier: NCT05111431(First registration date: 20/10/2021)
Characteristics of patients who died in the Hospital Emergency Service during the SARS-CoV-2 pandemic: a retrospective cohort study in a tertiary hospital in Spain.
Authors: González Iria Sanlés , Abejez Laura Grimal , Muñoz Judith Serrat , Boter Neus Robert , Egea Antonia Segura , Molas Anna Carreres , Valle Héctor Alonso , Molero Jessica Alonso , Dierssen-Sotos Trinidad , Gómez-Acebo Inés
Published: October 2023

Objective:
The objective of this study is to analyze the characteristics of patients who died in the Hospital Emergency Department (HED) of a Spanish third-level hospital, with a special focus on those who died due to SARS-CoV-2.
Methods:
A retrospective cohort study was conducted, including all patients over 18 years old who died in the Hospital Emergency Department (HED) of a Spanish third-level hospital located in Badalona, Spain, from June 2019 to December 2020. Various sociodemographic, clinical, and diagnostic variables of the patients were analyzed to identify potential risk factors associated with mortality.
Results:
During the first wave of the COVID-19 pandemic, a total of 72 patients died in the HED, representing a 42% increase compared to the pre-pandemic period. Of the deceased patients, 11% were attributed to SARS-CoV-2. Furthermore, it was found that patients who died from SARS-CoV-2 during the first wave were significantly younger than those in the second wave, with an average age of 78.6 ± 3.1 years in the first wave and 91.8 ± 4.8 years in the second wave. No significant differences were found regarding gender or associated comorbidities.
Conclusions:
Overall, the mortality rate at the HED in relation to COVID-19 was low, and infected patients died at younger ages during the first wave compared to the second wave.
Characterization of Smallholder Irob Cattle Production System: Contributions to Develop a Breeding Program
Authors: Abraham Hagos
Published: October 2023

An exploratory survey (i) to study livestock production system, some reproductive and productive performance traits of cattle and (ii) to recognize constraints to cattle production was conducted using 120 farmers keeping indigenous Irob cattle breed in selected districts of Tigray, Ethiopia. For this study, six tabias (the smallest administrative unit consisting of several villages) were selected using purposive sampling method although households from each tabia were randomly selected. Mixed crop-livestock farming system dominates the study area. Overall herd size was 5.14 ± 2.68, with each herd comprising of 1.66 ± 1.18 cows, 1.42 ± 0.88 oxen, 0.46 ± 0.71 heifers, 0.45 ± 0.69 bulls and 1.15 ± 0.90 calves. Cattle are reared for various functions. The main reasons mentioned for cattle keeping are draught power (I = 0.43), milk production for home consumption (I = 0.32), income (I = 0.15), manure as fertilizer (I = 0.06) and crop threshing (I = 0.04). Major feed resources were natural pasture, crop residue and cactus pear (opuntia ficus-indica). Least squares means (± S.E) for age at first services (AFS), age at first calving (AFC), calving interval (CI), days open (DO), daily milk yield (DMY) and lactation length (LL) based on in-person survey was 28.26 ± 3.85 months, 37.39 ± 5.47 months, 15.53 ± 4.10 months, 6.54 ± 1.83 months, 1.72 ± 0.43 liters and 7.42 ± 1.99 months, respectively. However, performance traits considered were insignificantly (p > 0.05) differed between districts. Key cattle production constraints in order of significance as perceived by the respondents were feed shortage, disease and parasites incidence, absence of AI services, water scarcity and poor veterinary services. Hence, the study shown the worth of taking into account the production environment during developing breed improvement programs and recommends fit management system.
Repeatability of [15O]H2O PET Imaging for Lower Extremity Skeletal Muscle Perfusion: A Test-Retest Study
Authors: Christensen Nana Louise , Sørensen Jens , Bouchelouche Kirsten , Madsen Michael Alle , Buhl Christian Selmer , Tolbod Lars Poulsen
Published: October 2023

Background
[15O]H2O PET/CT allow non-invasive quantification of tissue perfusion and can potentially play a future role in the diagnosis and treatment of peripheral artery disease. We aimed to evaluate the reliability of dynamic [15O]H2O PET imaging for measuring lower extremity skeletal muscle perfusion.
Results
Ten healthy participants underwent same-day test-retest study with six dynamic [15O]H2O PET scans of lower legs and feet. Manual volume-of-interests were drawn in skeletal muscles, and PET time-activity curves were extracted. K1 values (mL/min/100mL) were estimated using a single-tissue compartment model (1TCM), autoradiography (ARG), and parametric imaging with blood input functions obtained from separate heart scans. Resting perfusion values in the muscle groups of the lower legs ranged from 1.18–5.38 mL/min/100mL (ARG method). In the muscle groups of the feet, perfusion values ranged from 0.41–3.41 mL/min/100mL (ARG method). Test-retest scans demonstrated a strong correlation and good repeatability for skeletal muscle perfusion with an intraclass correlation coefficient (ICC) of 0.88 and 0.87 and a repeatability coefficient of 34% and 53% for lower legs and feet, respectively. An excellent correlation was demonstrated when comparing the VOI-based methods (lower legs: ICC = 0.96, feet: ICC = 0.99). Parametric images were quantitative with excellent agreement with the volume-of-interest-based ARG method (lower legs: ICC = 0.97, feet: ICC = 0.98).
Conclusion
Parametric images and volume-of-interest-based methods demonstrated comparable resting perfusion values in the lower legs and feet of healthy individuals. The largest variation was seen between individuals, whereas a smaller variation was seen between muscle groups. Repeated measurements of resting blood flow yielded a strong overall correlation for all methods.
Single intranasal immunization with attenuated Wuhan-like SARS-CoV-2 provides highly effective cross-protection against Delta and Omicron VOCs
Authors: Faizuloev Evgeny , Gracheva Anastasiia , Korchevaya Ekaterina , Ammour Yulia , Smirnova Daria , Khokhlova Darya , Andrey Drokov , Pankratov Andrey , Trunova Galina , Khokhlova Varvara , Leneva Irina , Svitich Oxana , Zverev Vitaly
Published: October 2023

Despite the end of the COVID-19 pandemic, the problem of vaccine prevention of this disease appears highly relevant. The emergence and widespread distribution of the Omicron SARS-CoV-2 variant of concern (VOC) and its sublineages has dramatically reduced the efficacy of vaccination with licensed vaccines. The possible approach to solving this problem is to develop a nasal live attenuated vaccine (LAV) capable of activating humoral, mucosal, and cell-mediated immunity, providing a prolonged immune response and cross-protection against different VOCs. The aim of the present study was to determine the immunization efficacy with attenuated cold-adapted Wuhan-like SARS-CoV-2 D-D2 strain against homologous and heterologous challenges. Single intranasal immunization of golden Syrian hamsters with D-D2 strain showed its high immunogenicity: seroconversion was evident in all immunized animals. The absence of infectious virus in the lung, nasal passages, and brains of immunized animals allows us to characterize immunity to SARS-CoV-2 as "sterile" consistent with the viral RNA concentration in the organs on the fourth-day post-challenge. Comparison of data on viral reproduction in organs, weight dynamics, and morphological changes in the lungs of immunized and unimmunized hamsters showed that attenuated Wuhan-like D-D2 strain provides highly effective protection against infection and development of pneumonia when challenged both with ancestral virus and heterologous Delta (B.1.617.2.122) and Omicron (sublineages BA.1 and BA.5.2) variants. Thus, attenuated SARS-CoV-2 variants have great potential for the development of highly effective nasal live COVID-19 vaccines on their basis.
Diversity of fungal community andquality evaluation of Spatholobus suberectus Dunn during the process of mildew
Authors: Xia Chunfeng , Zhao Yuchao , Liu Chunlan , Gao Yang
Published: October 2023

Spatholobus suberectus Dunn as a traditional Chinese herbal medicine, which is susceptible to being infected by molds during storage. In order to explore the diversity characteristics of fungal community and the quality evaluation of Spatholobus suberectus Dunn during the process of mildew. The study used high-throughput sequencing technology to detect the diversity characteristics of fungal community, high-performance liquid chromatography (HPLC) and ultraviolet spectrophotometry (UV-spectrophotometry) methods to detect the content of flavonoids, and enzyme-linked immunosorbent assay (ELISA) method to detect the content of Aflatoxins B1 (AFB1). The result showed that the fungi of Spatholobus suberectus Dunn samples during the process of mildew belonged to 14 phyla, 43 classes, 92 orders, 189 families, 336 genera, 432 fungal taxa. The species diversity of fungal community was the highest at the early stage of mildew, and the species richness of fungal community was the highest at the late stage of mildew. At the genus level, the dominant fungus at the early stage of mildew was not obvious, while the dominant fungus of samples at middle and late stages of mildew was Aspergillus. The content of AFB1 showed an upward trend and the content of flavonoids showed a downward trend during the process of mildew. In brief, the diversity of fungal community decreased gradually, the number of dominant flavus increased gradually, and the quality of Spatholobus suberectus decreased gradually during the process of mildew.
Enhancing the oxidative stability and bioaccessibility of resveratrol using food-derived nanoparticles
Authors: Ke Lijing , He Fangzhou , Yu Zhaoshuo , Wang Huiqin , PENG Weng Kung , Luo Sihao , Wang Leying , Zhang Yue , meng xiangyu , Jin Xuanlu , Huang Zongke , Deng Peishan , Zhou Jianwu , Wall Patrick , Rao Ping-Fan
Published: October 2023

This study explores the utilization of freshwater clam soup derived food nanoparticles (CFNPs) to encapsulate the antioxidant resveratrol (Res) which is found in red wine. We characterized the encapsulation properties and activities of the bound antioxidant. The results demonstrated that CFNPs can effectively encapsulate Res with a loading capacity exceeding 2.5%, and both encapsulation efficiency and bioaccessibility of over 70%, leading to a uniform particle size of 70.5 ± 0.07 nm and relatively low PDI (less than 0.2). CFNPs-Res exhibited an improved antioxidant stability under various conditions, with over 90% of antioxidant capacity retained after three-day storage at room temperature. The controlled-release profile of Res loaded in CFNPs-Res fits both first and Higuchi order kinetics and is more desirable than that of wine on its own and free Res solution. Examined by the simulated gastrointestinal digestion, CFNPs-Res showed a significantly higher antioxidant retention compared to free Res and wine on its own. We suggest that given there are nanoparticles in calm soup they may be in other foodstuffs with similar properties, and they too could be used to enhance the absorption of micronutrients and antioxidants. The use of nanoparticles to carry micronutrients and antioxidants could lead to a change in nutritional advice to increase the concentration of nanoparticle containing foods in the diet, carrying more bioaccessible micronutrients and antioxidants, in an attempt to make diets healthier and to tackle diet related disease.
Implementation of state health insurance benefit mandates for cancer-related fertility preservation: Following policy through a complex system
Authors: Su H. Irene , Kaiser Bonnie , Crable Erika , Ortega Ricardo Flores , Yoeun Sara W , Economou Melina , Fernandez Estefania , Romero Sally AD , Aarons Gregory A , McMenamin Sara B.
Published: October 2023

Background: A myriad of federal, state, and organizational policies are designed to improve access to evidence-based healthcare, but the impact of these policies likely varies due to contextual determinants, re-interpretations of and poor compliance with policy requirements throughout implementation. Strategies enhancing implementation and compliance with policy intent can improve population health. Critically assessing the multi-level environments where health policies and their related health services are implemented is essential to designing effective policy-level implementation strategies. California passed a 2019 health insurance benefit mandate requiring coverage of fertility preservation (FP) services for individuals at risk of infertility due to medical treatments to improve access to services that are otherwise cost-prohibitive. Our objective was to document and understand multi-level environment, relationships, and activities involved in using state benefit mandates to facilitate patient access to FP services.
Methods: We conducted a mixed-methods study and used the policy-optimized Exploration, Preparation, Implementation, Sustainment (EPIS) framework to analyze implementation of California’s fertility preservation benefit mandate (SB 600) at and between the state insurance regulator, insurer and clinic levels.
Results: Seventeen publicly available FP benefit mandate-relevant documents were reviewed, and four insurers, 25 financial, administrative and provider participants from 16 oncology and fertility clinics, three fertility pharmaceutical representatives, and two patient advocates were interviewed. The mandate and insurance regulator guidance represented two “Big P” (system level) policies that gave rise to a host of “little p” (organizational) policies by and between the regulator, insurers, clinics, and patients. Many little p policies were bridging factors to support implementation across levels and FP service access. Characterizing the mandate’s functions (i.e., policy goals) and forms (i.e., ways that policies were enacted) led to identification of (1) intended and unintended implementation, service, and patient outcomes; (2) implementation processes by level, EPIS phase; (3) actor-delineated key processes and heterogeneity among them; and (4) inner and outer context determinants that drove adaptations.
Conclusions: Following the mid- and down-stream implementation of a state health insurance benefit mandate, data generated will enable development of policy level implementation strategies, evaluation of determinants and important outcomes of effective implementation, and design of future mandates to improve fit and fidelity.