bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of Cross-directional and Cross-Wall Variations of Passive Biaxial Mechanical Properties of Rat Myocardium
Authors: Ngwangwa Harry , Nemavhola Fulufhelo , Pandelani Thanyani , Msibi Makhosasana , Mabuda Israel , Davies Neil , Franz Thomas
Published: September 2021

Heart myocardia are critical to the facilitation of heart pumping and blood circulating around the body. The biaxial mechanical testing of the Left Ventricle (RV) is utilised to build the computa-tional model of the whole heart with little importance given to the unique mechanical properties of Right Ventricle (RV) and Mid-wall (MDW). Most of those studies focussed on the LV of the heart, and then apply the obtained characteristics with a few modifications to the right side of the heart. However, that view has been contested over time with the realisation that the right side of the heart possesses its own unique mechanical properties that are widely distinct from that of the left side of the heart. This paper is aimed at reporting and evaluating the passive mechanical property dif-ferences in the three main walls of the rat heart based on biaxial tensile test data. Fifteen mature Wistar rats weighing 225 ± 25 g were euthanised by inhalation of 5 % halothane. The hearts were excised after which all the top chambers comprising the two atria, pulmonary and vena cava trunks, aorta and valves are all dissected out. Then 5 x 5 mm sections from the middle of each wall were carefully dissected with a surgical knife to avoid over-prestraining the specimens. The specimens were subjected tensile test. The elastic moduli, peak stresses in the toe region and stresses at 40 % strain, anisotropy indices as well as the stored strain energy in the toe and linear region up to 40 % strain are used for statistical significance tests. The following are the main findings of this study: (1) LV and MDW tissues have relatively shorter toe regions of 10 - 15 % strain as compared to RV tissue whose toe region extends up to twice as much as that (2) LV tissues have higher strain energy storage in the linear region despite being lower in stiffness than the RV (3) the MDW has the highest strain energy storage along both directions which might be directly related to its high level of anisotropy. These findings, though for a specific animal species at similar age and around the same body mass, emphasize the importance of application of wall specific material parameters to obtain accurate ventricular hyperelastic models. The findings further enhance our understanding of the desired mechanical behaviour of the different ventricle walls.
Traceability of Sustainable and Safe Fisheries Supply Chain Management Systems using Radio Frequency Identification Technology
Authors: Rahman Labonnah Farzana , Alam Lubna , Marufuzzaman Mohammad , Sumaila Ussif Rashid
Published: September 2021

At present, sustainability and emerging technology are the most expressed issues in any supply chain management (SCM) sector. At the same time, pandemic makes consumers more concerned regarding health, and safe food with a sustainable way to access the current market. Thus, supervision and monitoring of product quality with symmetric traceability information in fresh food and fisheries SCM is significant. Research on food safety and traceability systems based on blockchain, internet of service (IoT), wireless sensor networks (WSN), and radio frequency identification (RFID) provides the solution of constancy from production to consumption. This review focused on the RFID-based traceability systems in fisheries SCM, which have been employed globally in the last fifteen years to ensure fish quality and security. Additionally, a summarized comparison study has presented different sectors’ traceability systems using RFID and their advantages over real-time applications. The outcome of this study will help future researchers to solve the crisis in terms of trust between consumers and the fisheries SCM. Thus, this review would be a guideline and solution for enhancing the reliability of RFID-based traceability in food SCM systems to ensure the integrity and reducing the opacity and asymmetry in the product information.
On the Tensile Creep Deformation Behaviour of Wrought Single-phase γ-TiAl
Authors: Saha Mainak
Published: September 2021

Creep deformation behaviour in single phase γ-TiAl alloy has been an extensively studied topic since the late 1970s. A lot of literatures have reported creep behaviour of γ-TiAl alloys, manufactured using different processing techniques [1]–[7]. The present discussion revisits the original work on understanding the tensile creep deformation behaviour of wrought single-phase γ-TiAl alloy by Hayes et al. [8] and is aimed to develop an understanding of steady state creep, through strain vs strain rate and strain vs ln(strain rate) plots. Besides, it also attempts to study the variation of stress exponent with temperature between 760-900⁰C and also, to determine activation energies using the two most common approaches, namely: Zener-Hollomon (Z-H) [9] and Sherby-Dorn (S-D, temperature compensated time approach) [10] for stress levels of 69 and 103.4 MPa between 760-900⁰C.
Implementasi Undang – undang Nomor 39 Tahun 2007 Tentang Cukai Terhadap Produk Hasil Pengolahan Tembakau Lainnya Berupa Liquid Personal Vaporizer yang tidak Dilengkapi oleh Pita Cukai
Authors: Widodo Dimas Tragari Eldo , Bidasari Anindya , Suciati Suciati
Published: September 2021

The background of this research is that the determination of Customs collection on Liquid Personal Vaporizer can be concluded that the government has found an answer to the debate that has been happening in Indonesia regarding the prohibition of Personal Vaporizer. As for the formulation of the problem in this research is How the Implementation of “Law No. 39 of 2007” concerning Customs for other tobacco processing products in the form of Liquid Personal Vaporizer, How is the solution or legal remedy in the process of implementing Customs on other tobacco processed products in the form of Liquid Personal Vaporizer which is not equipped with Customs stamps. The type of research in this research is sociological juridical which in other words is a type of sociological legal research and can also be called field research, which examines the applicable legal provisions and what happens in reality in society. While the dataVanalysis technique uses a qualitative descriptive method. The conclusion obtained by the researchers from the results of this research is that although most of them are regulated by ministerial regulations, the application of Customs for HPTL products in the form of Liquid Personal Vaporizers is still based on Law No.39 of 2007 concerning Customs for all regulations related to the application of Customs. And also the legal settlement for Liquid Personal vaporizer that is not equipped with Customs stamps in the Malang Customs Customs KPPBC area using non-penal channels for the settlement.
Pont Evksinskiy – 2021 : materials of XII All-Russian scientific and applied conference for young scientists on the water systems problems, dedicated to the 150 th anniversary of the Sevastopol Biological Station ‒ A. O. Kovalevsky Institute of Biology of the Southern Seas of RAS, Sevastopol, 20–24 September, 2021
Authors:   A. O. Kovalevsky Institute of Biology of the Southern Seas
Published: September 2021

The book includes materials of young scientists from Russia and the Republic of Abkhazia, revealing various aspects of modern marine and freshwater biology. Abstracts highlight the results of scientific research in the field of population dynamics and genetic differentiation of aquatic organisms, the features of their life cycle. The book present works on the influence of abiotic and anthropogenic environmental factors on the physiological status of aquaculture species. A number of works describes the capabilities of modern research methods applied in marine and freshwater biological studies, such as metabarcoding, "frame" and "rake method" for detecting beach debris, NGS sequencing, and satellite monitoring. In addition, the book reveals the features of the functioning of coastal ecosystems. The book is valuable for young scientists in the field of marine and freshwater biology, water ecology, biotechnology, aquaculture, marine ecology and zoology
Modulated AC/DC Crude Desalting Technology Application & Best Practices
Authors: White Ramsey , Mulas Simone , Domini Pier , Lopez Miguel , Abusittah Faris
Published: September 2021

The Modulated AC/DC Crude Desalting technology was successfully commissioned at several Saudi Aramco facilities. Enhancements to desalting performance and optimization of plant operating expenditures were realized. Benefits of the Modulated AC/DC Desalting technology, installation and operational best practices and a comparison to conventional AC technology is shared in the paper.

The conventional AC desalting technology was replaced with the Modulated AC/DC Crude Desalting technology at some Saudi Aramco facilities. After the successful commissioning, the performance of the new units was tested in one of these facilities to identify operating limits, such as maximum water cut and minimum demulsifier injection at the production header, in which the stable operation is sustainable. A comparison of the performance of the technology compared to that of previous conventional AC desalting technology was conducted through analysis of grid/plate voltage stability, demulsifier injection rate, wash water rates and crude quality parameters. Some enhancements to the process were also introduced which resulted in realizing additional benefits.

The technology resulted in several benefits, including: (1) A reduction in the required demulsifier injection rate during the testing period compared to the same time period from the previous year, leading to significant cost savings; (2) Ability to maintain normal operations beyond the design water cuts of the facility; (3) No major grid outages since installation; (4) Additional data that can be used to diagnose separation performance as each transformer provides a number of feedback signals to DCS that are good indicators of the separation process. Based on the observations and analysis, the Modulated AC/DC Crude Desalting Technology has several advantages over the conventional AC Crude Desalting Technology in regards to crude desalting performance and process stability.

The Modulated AC/DC Crude Desalting technology at Saudi Aramco was the first installation in Saudi Arabia for Arab Light crude oil. The paper captures Saudi Aramco’s experience and best practices that other companies can find beneficial in their efforts to maintain crude quality and reduce operating expenditures.
Overcoming Lost Circulation Risks in Low Fracture Gradient Formations with a New Tailored Spacer System
Authors: Hugentobler Kory , Shine Joseph M. , De La Cruz Sasso Alejandro , Shamsan Abdulmalek , Patil Sandip , Agapiou Kyriacos
Published: September 2021

In certain regions of oil and gas operations, lost circulation is a common occurrence, especially when a majority of the openhole exposed during primary cementing is carbonate-based formations. This can lead to lost circulation risks in most applications. To overcome lost circulation risks during primary cementing, a new tailored spacer system shows to improve the cement placement success. The manuscript discusses the quality assurance and performance testing with field cases demonstrating the value contributions of the spacer for achieving zonal isolation requirements as well as the top of cement objectives. The work efforts presented shows a spacer meeting and sometimes showing incremental wellbore strengthening in comparison to the published literature for existing available spacers used to overcome similar lost circulation risks.
Mechanistic Model for the Design and Operation of an Intermittent Gas Lift System for Liquid Loaded Horizontal Gas Wells
Authors: Croce Daniel , Zerpa Luis
Published: September 2021

Removing stagnant liquid in a loaded horizontal gas well remains an unsolved challenge. Current practices for horizontal well deliquification are limited in terms of reliability and continuity, resulting on increased OPEX and CAPEX, behind down time and additional equipment installation. Experimental evaluation of a proposed artificial lift method for horizontal well deliquification, showed average removal efficiencies of 75% of the stagnant liquid volume. The experimental facility consisted of an experimental flow loop, that replicates conditions of liquid-loaded horizontal wells, with a horizontal section of 40 feet and a vertical section of 40 feet. The method is based on the chamber lift principles, using intermittent injection of gas at high pressure and low volumetric flow rates to the horizontal section of the well. Removal efficiency increased by 12% by using saccharidic additives and sodium chloride, to increase the surface tension between the injected gas (compressed air) and the liquid (water). This work presents a mechanistic model of the proposed artificial lift method, based on the momentum balance of the gas and the liquid slug flowing along the horizontal and vertical sections of the system, including numerical regressions for the prediction of the surface tension and viscosity of the liquid mixture as a function of temperature and the concentration of the tested additives. The model is used to determine the required available injection pressure at surface, and the location of the valve mandrel, as same as to estimate the removed liquid volume, discharge volumetric rate, and discharge pressure of the liquid slug at the surface facilities. The model is validated against experimental data obtained from the experimental flow loop.
Analysis of Vertical Permeability and Its Influence on CO2 EOR and Storage in a Carbonate Reservoir
Authors: Ren Bo , Jensen Jerry , Lake Larry , Duncan Ian , Male Frank
Published: September 2021

The objective of this study is to improve understanding of the geostatistics of vertical (bed-normal) permeability (kz) and its influence on reservoir performance during CO2 enhanced oil recovery (EOR) and storage. kz is scrutinized far less often than horizontal permeability (kx, ky) in most geological and reservoir modeling. However, our work indicates that it is equally important to understand kz characteristics to better evaluate their influence on CO2 EOR and storage performance prediction.

We conducted this study on about 9,000 whole-core triaxial permeability (kx, ky, kz) measurements from 42 wells in a San Andres carbonate reservoir. We analyzed kz data, including heterogeneity, correlation, and sample sufficiency measures. We analyzed wells with the largest and smallest fractions of points with kz > kmax = max(kx, ky), to explore geological factors that coincided with large kz. We quantified these geological effects through conditional probabilities on potential permeability barriers (e.g., stylolites).

Every well had at least some whole-cores where kz > kmax. This is a statistically justifiable result; only where Prob(kz > kmax) is statistically different from 1/3 are core samples non-isotropic. In conventional core data interpretation, however, modelers usually assume kz is less than kmax. For the well with the smallest fraction (11%) of cores where kz > kmax, the cumulative distribution functions differ and coincides with the presence of stylolites. We found that kz is about twice as variable as kx in many wells. This makes kz more difficult to interpret because it was (and usually is) heavily undersampled.

To understand the influence of kz heterogeneity on CO2 flow, we built a series of flow simulation models that captured these geostatistical characteristics of permeability, while considering kz realizations, flow regimes (e.g., buoyant flow), CO2 injection strategies, and reservoir heterogeneity. CO2 flow simulations showed that, for viscous flow, assuming variable kx similar to the reservoir along with a constant kz/kx = 0.1 yields a close (within 0.5%) cumulative oil production to the simulation case with both kx and kz as uncorrelated variables. However, for buoyant flow, oil production differs by 10% (at 2.0 hydrocarbon pore volume HCPV of CO2 injected) between the two cases. Such flows could occur for small CO2 injection rates and long injection times, in interwell regions, and/or with vertically permeable conduits.

Our geostatistical characterization demonstrates the controls on kz in a carbonate reservoir and how to improve conventional interpretation practices. This study can help CO2 EOR and storage operators refine injection development programs, particularly for reservoirs where buoyant flow exists. More broadly, the findings potentially apply to other similar subsurface buoyancy-driven flow displacements, including hydrogen storage, geothermal production, and aquifer CO2 sequestration.
Improved Prediction of Sand Erosion by Accurate Particle Shape Representation in CFD-DEM Modelling
Authors: Agrawal Madhusuden , Haghnegahdar Ahmadreza , Bharadwaj Rahul
Published: September 2021

Predicting accurate erosion rate due to sand particles in oil and gas production is important for maintaining safe and reliable operations while maximizing output efficiency. Computational Fluid Dynamic (CFD) is a powerful tool for erosion prediction as it provides detailed erosion pattern in complex geometry. In an effort to improve accuracy of erosion prediction, this paper proposes an algorithm to accurately represent particle shape in CFD erosion simulation through coupling with Discrete Element Method (DEM) for non-spherical shape particles. The fluid motions are predicted by CFD and the particle movements (including particle-particle and particle-wall collisions) and fluid-particle interaction are calculated using DEM.

It is widely known that sand particles are of finite volume with a non-spherical shape, accurate representation of sand particles is important in CFD modelling for accurate prediction of erosion rate. Traditional CFD approach usages lagrangian tracking of sand particles through Discrete Phase Model (DPM), where a particle is assumed as a point mass for the calculation of trajectory and particle-wall interaction. Particle impact velocity and impact angle are important parameter in determining erosion. Assumption of point mass in DPM approach, will not capture particle-wall interaction accurately especially when particles are of non-spherical in shape. In additional, DPM approach ignores particle-particle interactions. This can adversary affect the accuracy of erosion predictions. Integrating non-spherical DEM collision algorithm with CFD erosion simulation, will overcome these limitations and improve erosion predictions.

Benefits of this CFD-DEM erosion modelling was demonstrated for gas-solid flow in a 2" pipework which consists of out-of-plane elbows in series and blind-tees. Experimental dataset [1] for erosion pattern on each elbow was used to validate CFD predictions. Three different erosion CFD simulations were performed, traditional DPM based CFD simulation, CFD-DEM simulation for spherical shape particles and CFD-DEM simulation for non-spherical shape particles. CFD-DEM coupled simulations clearly show an improvement on erosion predictions compared to DPM based CFD simulation. Effect of non-spherical shape on rebound angle during particle-wall collision is captured accurately in CFD-DEM simulation. CFD-DEM simulation using non-spherical particle, was able to predict erosion pattern closer to experimental observations.

This paper will demonstrate an increase in accuracy of sand erosion prediction by integrating DEM collision algorithm in CFD modelling. The prediction results of elbow erosion subject to a condition of dilute gas-particle flow are validated against experimental data. Improved prediction of erosion risk will increase the safety and reliability of oil & gas operations, while maximizing output efficiency.
Development of a Mentoring Program as a Strategy for the Empowerment of Young Professionals in the Strengthening of Their Soft Skills
Authors: Ovalle Oscar , Estepa Claribeth , Hoyos Maria , Diaz Claudia , Jaramillo Sandra , Rada Angelica , Pastor Paola
Published: September 2021

Objectives/Scope

Contribute to the development of the profile of young professionals based on a balance between personal and work life, strengthening the self-confidence of the individual and leaving aside the influence of personal aspects in the professional field. Provide a deeper vision of their personal objectives from the discovery of the personality and the strengthening of soft skills by implementing an innovative methodology

Methods, Procedures, Process

The program implements a structured, simplified and staggered methodology for the identified needs, attracting qualified young people and matching them with the most appropriate mentors, ensuring that throughout the mentoring process, a different focus and objective with the necessary durability is worked session by session. With the development of three books, SPE Colombia Section provides all the necessary tools to work on different aspects, objectives and evaluate the learning that takes place in each session, which are:

Mentor-Mentee connection Strengthening your profile Leadership and decision making Breaking paradigms and overcoming obstacles Evaluating learning.

In its two versions, the program has had the participation of 92 young professionals and 92 Seniors in total. It has managed to obtain a satisfaction level of 92% and has met the goals of the young people by 88%. More than 300 sessions and 500 hours of mentoring have been carried out. 10 training talks have been held for mentors and mentees. 3 guide books for mentor and mentee with all activities and minimum requirements per session. The Mentoring program works for different purposes, especially based on the age and needs of the individual". It is a unique relationship between individuals. There is no equal mentoring, different interpersonal exchanges and patterns of idiosyncratic interactions define and shape the relationship. However, two main contributions emerge for the mentee: 1) As a space in itself for the exploration of ideas and to receive support of different kinds, and 2) As an indirect learning alliance by the acquisition of valuable information through the experience.
DFIT: An Interdisciplinary Validation of Fracture Closure Pressure Interpretation Across Multiple Basins
Authors: Buijs Hernán
Published: September 2021

Recent papers on pre-frac tests have proposed fracture closure pressure interpretation methodologies that lead to an earlier, higher stress estimation than the ones estimated from well-established practices. These early time estimations based on the fracture compliance method lead the practitioner to utilize unrealistic permeability, stress, and fracture pressure models. This, in turn, has a severe impact on the modeled fracture geometries which hinders the hydraulic fracture optimization process. A multi-basin analysis of pre-frac tests from the North Sea, Europe, Russia, North Africa and South America is presented to support traditional closure estimation techniques. The validity of traditional minimum stress interpretation techniques will be reinforced through multiple case histories by comparing permeability estimates from the time required for the fracture to achieve closure during diagnostic injections, after-closure analysis, core, pressure build up and rate transient analysis. Results will be supported further by fiber optics and production logging tool (PLT) driven flow allocation, fracture geometry assessment through micro seismic and sonic anisotropy, and diagnostic injections numerical inversions.
Simulation of Subsea and Platform Production Schemes to Quantify Flow Assurance Risks under Transient and Steady State Conditions in Offshore Kuwait
Authors: Al-Safran Eissa
Published: September 2021

In offshore production, the type of field development scheme is crucial aspect due to its associated flow assurance risks, which affect project economic, safety, and sustainability. The objective of this study is to simulate and evaluate two offshore field development schemes, namely subsea and platform in offshore Kuwait. Further objective is to carry out detailed transient simulation study on the subsea scheme to investigate flow assurance risks related to terrain slugging, and hydrates formation during shut-in and re-start transient events. The evaluation of the two schemes is based on the associated flow assurance risks, and project economics. Steady state simulations are used to identify the feasible production scheme, which is further simulated under transient shut-in/restart events to investigate flow assurance risks related to terrain slugging and hydrates formation. The steady state simulation results of this study showed that flow assurance risks such as hydrates and pipeline corrosion are significant in both production schemes. To mitigate these risks, sixteen different field development designs of both production schemes were simulated and economically evaluated. Results revealed that the subsea multiphase development scheme with 10-in. ID carbon steel multiphase flowline and 0.3-in. thick polypropylene thermal insulation is the optimum design. Consequently, the optimum design is further analyzed under transient conditions, resulting in appreciable risk of terrain slugging due to hilly-terrain pipeline configuration, especially for the low production rate cases. The transient shut-in/restart simulation results revealed a risk of hydrates formation due to cooling effect during shut-in, which is mitigated by MEG injection. In conclusion, the subsea multiphase flow scheme is selected over platform scheme due to manageable flow assurance risks, low capital investment cost, and minimum environmental impact. This study would enable Kuwait Oil Company to evaluate different offshore development schemes to ensure sustainable production with safe operation and protected environment.
Prediction of High Viscosity Liquid/Gas Two-Phase Slug Length in Horizontal and Slightly Inclined Pipelines
Authors: Shaaban Omar , Al-Safran Eissa
Published: September 2021

The production and transportation of high viscosity liquid/gas two-phase along petroleum production system is a challenging operation due to the lack of understanding the flow behavior and characteristics. In particular, accurate prediction of two-phase slug length in pipes is crucial to efficiently operate and safely design oil well and separation facilities. The objective of this study is to develop a mechanistic model to predict high viscosity liquid slug length in pipelines and to optimize the proper set of closure relationships required to ensure high accuracy prediction. A large high viscosity liquid slug length database is collected and presented in this study, against which the proposed model is validated and compared with other models. A mechanistic slug length model is derived based on the first principles of mass and momentum balances over a two-phase slug unit, which requires a set of closure relationships of other slug characteristics. To select the proper set of closure relationships, a numerical optimization is carried out using a large slug length dataset to minimize the prediction error. Thousands of combinations of various slug flow closure relationships were evaluated to identify the most appropriate relationships for the proposed slug length model under high viscosity slug length condition. Results show that the proposed slug length mechanistic model is applicable for a wide range of liquid viscosities and is sensitive to the selected closure relationships. Results revealed that the optimum closure relationships combination is Archibong-Eso et al. (2018) for slug frequency, Malnes (1983) for slug liquid holdup, Jeyachandra et al. (2012) for drift velocity, and Nicklin et al. (1962) for the distribution coefficient. Using the above set of closure relationships, model validation yields 37.8% absolute average percent error, outperforming all existing slug length models.
Experimental Study and History Match of Near-Miscible WAG Coreflood Experiments on Mixed-Wet Carbonate Rocks
Authors: El Faidouzi Mohamed Mehdi
Published: September 2021

Water-alternating-gas (WAG) injection, both miscible and immiscible, is a widely used enhanced oil recovery method with over 80 field cases. Despite its prevalence, the numerical modeling of the physical processes involved remains poorly understood, and existing models often lack predictability. Part of the complexity stems from the component exchange between gas and oil and the hysteretic relative permeability effects. Thus, improving the reliability of numerical models requires the calibration of the equation of state (EOS) against phase behavior data from swelling/extraction and slim-tube tests, and the calibration of the three-phase relative permeability model against WAG coreflood experiments.

This paper presents the results and interpretation of a complete set of two-phase and thee-phase displacement experiments on mixed-wet carbonate rocks. The three-phase WAG experiments were conducted on the same composite core at near-miscible reservoir condition; experiments differ in the injection order and length of their injection cycles.

First, the two-phase water/oil and gas/oil displacement experiments and first cycles of WAG were used to estimate the two-phase relative permeabilities. Then, a history matching procedure over the full set of WAG cycles was carried out to tune the Larsen and Skauge WAG hysteresis model—namely the Land gas trapping parameter, the gas reduction exponent, the residual oil reduction factor and three-phase water relative permeability.

The second part of this paper is dedicated to the value of information (VOI) analysis of the coreflood work program to assist the decision to proceed with a capital intensive WAG pilot at an offshore oilfield. Stochastic simulation of WAG injection using a fine scale sector model allowed to quantify the reduction in the range of uncertainty of key metrics—such as oil recovery, peak gas production and injectivity—linked with the additional SCAL information.

The current study highlights the impact of the WAG injection sequence on the oil recovery and trapping mechanism. In addition, it is shown that the relative permeabilities and hysteresis model calibrated on one particular set of injection cycles fail to capture the WAG performance when the injection cycles are altered. Finally, the VOI methodology demonstrated the value enhancement from the coreflood work program.
Efficacy And Safety Of EUS-Guided Multimode Ablation Compared With Conventional Chemotherapy In Unresectable Pancreatic Cancer Patients
Authors: Ruan Xixian , Zhang Zinan , Long Xiuyan , Fang Ning , Yu Xiaoyu , Qiu Jianing , Long Yu , Tian Li , Wang Xiaoyan
Published: September 2021

Background & Aims: To compare the feasibility and safety between multimode endoscopic ultrasound-guided radiofrequency ablation (EUS-RFA) and conventional chemotherapy in unresectable pancreatic ductal adenocarcinoma (PDAC).Methods: All the pathologically confirmed unresectable PDAC located in the head of the pancreas patients who underwent multimode EUS-RFA or conventional chemotherapy were retrospectively enrolled from June 2018 and April 2019. Patients who underwent multimode EUS-RFA (Group A) was performed through HybridTherm probe(HTP). Patients in Group B accepted nab-Paclitaxel plus Gemcitabine or S-1 plus Gemcitabine. The comparison between efficacy and safety of multimode EUS-RFA and conventional chemotherapy were analyzed by T test and MannWhitney test. A multivariate analysis was performed for each prognostic factor using the Cox proportional hazards model.Results: A total of 10 unresectable PDAC patients were retrospectively enrolled in Group A (mean size 9.46±5.94 cm3, range 2.00-21.09 cm3) and 9 patients in Group B (mean size 14.02±5.81cm3, range 4.60–24.62 cm3). The tumor size was significantly reduced before and after undergoing multimode EUS-RFA (P = 0.005), with an average tumor volume reduction of 38.1%.The tumor size was not significantly changed in Group B (P = 0.452). Statistically significant difference was observed in tumor size between Group A and Group B after treatment (P = 0.033). All patients died because of the progress of the tumor. The median lifetime from Group A&B was 9 months ranged 3-18 months VS 7 months ranged 1-7 months (P = 0.001). Overall no severe adverse events occurred in both groups.Conclusion: EUS-guided multimode ablation has the more feasibility in the treatment of unresectable pancreatic cancer than conventional chemotherapy. In this article, the limited data seems to show the trend of tumor shrinkage, pain relief, lifetime prolongation. Further studies are needed, such as expanding the sample size of patients and comparing the feasibility and safety among all the treatment.
Hydrolysis of the Kitchen Waste through Dry Anaerobic Digestion - A Sustainable Environmental Practice for its Effective Management
Authors: Agrawal Akanksha , Chaudhari Parmesh Kumar , Ghosh Prabir
Published: September 2021

Population explosion coupled with rapid industrialization and urbanization has led to accumulation of food waste. Nearly, 1.3 billion tons of food waste has been encountered annually which poses a serious threat to the environment and human beings. Therefore, it has become imperative to look for the sustainable environmental practices to manage huge quantum of the waste. Anaerobic Digestion (AD) has emerged as techno economical viable solution with the aim of resource as well as energy recovery to combat the global energy crisis. In this study, an attempt has been made to study the hydrolysis of kitchen waste through dry anaerobic digestion being a suitable technology for treating organic wastes with varying composition and its superiority over the wet digestion. Laboratory scale batch studies were conducted on kitchen waste using three different dry fermenters of total volume 4-litre operating under mesophilic regime for duration of 32 days. The reactors were simultaneously operated with the retention time of 1 day, 2 day and 4 days, respectively. Comparative performance of leachate generation during hydrolysis reveals that reactor with 1-day retention time generates maximum leachate with high COD of 244 g/l and VFA of 12.99 g/l. The specific rate constants for hydrolysis of kitchen waste through dry fermentation with retention time of 1 day, 2 days, 4 days were found to be 0.063, 0.054 and 0.027 day− 1, respectively.
Who Wants To Improve Collaboration in Services for Individuals with Chronic Conditions? Specialists and Rural General Practitioners Taking Action in a Fragmented Health Care System
Authors: Tomaschek Rebecca , Gemperli Armin , Essig Stefan
Published: September 2021

Introduction

Strategies to improve fragmented care for individuals with chronic conditions can be futile if those health care professionals who would have benefited are not engaged. We aimed to explore motivation and previous collaboration quality of general practitioners (GPs) and specialists who participate in an intervention study to improve their collaboration, and GPs who do not participate.
Methods

Explorative survey among rural GPs and specialists for spinal cord injury (SCI) participating in an intervention to improve collaboration, and non-participating GPs, from August to October 2020, in Switzerland.
Results

Eight GPs and 13 specialists of the intervention study and 23 non-participating GPs took part. Specialists were from various medical disciplines. Participating GPs were located farther away from a hospital and consulted a higher number of patients. Overall, the collaboration quality at the primary-secondary care interface was good. Whereas specialists and participating GPs were mostly satisfied with their collaboration, non-participating GPs’ reported a lower quality regarding some aspects of collaboration. Furthermore, differences in collaboration quality between general chronic care and SCI specific care could be observed.
Conclusion

The collaboration quality was rather high in participating physicians. The benefit of the intervention would have been higher in non-participating than participating GPs. When participation is optional, interventions to improve collaboration likely do not achieve the effect that would actually be possible.
Atrial Fibrillation Detection Using Feedforward Neural Network
Authors: Chen Yunfan , Zhang Chong , Liu Chengyu , Wang Yiming , Wan Xiangkui
Published: September 2021

Atrial fibrillation is one of the most common arrhythmias in clinics, which has a great impact on people's physical and mental health. Electrocardiogram (ECG) based arrhythmia detection is widely used in early atrial fibrillation detection. However, ECG needs to be manually checked in clinical practice, which is time-consuming and labor-consuming. It is necessary to develop an automatic atrial fibrillation detection system. Recent research has demonstrated that deep learning technology can help to improve the performance of the automatic classification model of ECG signals. To this end, this work proposes effective deep learning based technology to automatically detect atrial fibrillation. First, novel preprocessing algorithms of wavelet transform and sliding window filtering (SWF) are introduced to reduce the noise of the ECG signal and to filter high-frequency components in the ECG signal, respectively. Then, a robust R-wave detection algorithm is developed, which achieves 99.22% detection sensitivity, 98.55% positive recognition rate, and 2.25% deviance on the MIT-BIH arrhythmia database. In addition, we propose a feedforward neural network (FNN) to detect atrial fibrillation based on ECG records. Experiments verified by a 10-fold cross-validation strategy show that the proposed model achieves competitive detection performance and can be applied to wearable detection devices. The proposed atrial fibrillation detection model achieves an accuracy of 84.00%, the detection sensitivity of 84.26%, the specificity of 93.23%, and the area under the receiver working curve of 89.40% on the mixed dataset composed of Challenge2017 database and MIT-BIH arrhythmia database.
Study On Laying Performances, Blood Biochemical Indicators, Feather Condition And Antibody Titers of Layer Breeders Among Different Tiers In Mating Cages During The Peak Laying Period*
Authors: LI Yan , MA Rui-yu , WAN Yi , QI Renrong , LI Jun-ying , LIU Wei , CUI Hai-jun , ZHANG Xin , LIU Zhejie , ZHAN Kai
Published: September 2021

The present study was conducted to determine the effect of cage tier on laying performances, blood biochemical indicators, feather condition and antibody titers of layer breeders among different tiers in mating cages during the peak laying period. All birds (Hy-Line Brown parent stock breeders) at 27 weeks of age were housed in 4-tier mating cage. Laying performances, egg quality characteristics, blood biochemical indicators, antibody titers and feather condition were measured. The highest laying rate was recorded at 2nd tier, followed by 4th tier and 3rd tier, and the lowest at 1st tier. There were no significant differences among different tiers in terms of percentage of defective eggs and hatchability performances. Yolk color was significantly lower at 2nd tier than at other tiers. However, no distinct differences in egg weight, shell weight, shell color, shell breaking strength, egg shape index, yolk weight, albumen height, haugh units were observed. Concentrations of serum CK, T-AOC, SOD, GPx and MDA, and the antibody titers did not change substantially among different tiers. Moreover, the average feather score for each individual part of the body and an overall average score for birds were not significantly different. We confidently conclude that cage tier may be a contributing factor for layer performances. These findings will be helpful for application of natural mating system in layer industry.
Dl-3-n-Butylphthalide Promotes Cardiac Function, Inhibit Oxidative Stress and Myocardial Apoptosis of Chronic Heart Failure Mice via Stimulating Nrf2/HO-1 pathway
Authors: Wang Zhongyu , Zhang Yan , Yang Chun , Yang Hongliang
Published: September 2021

PurposeHeart failure (HF) continues to threat the human health and plagues the world, however, there are limited effective drugs for HF. We aimed to investigate the protective effect of Dl-3-n-Butylphthalide (NBP) on myocardial injury in heart failure mice, and to study regulation mechanisms with Nrf2/HO-1/Ca2+-SERCA2a axis. MethodsSixty C57BL/6J mice were grouped into five groups using a random number table: sham group (Sham), Heart Failure model group (HF), Heart Failure+ NBP group (HN), Heart Failure+NBP+Nrf2 inhibitor (HNM), Heart Failure+ NBP + calmodulin-dependent protein kinase II (CaMKⅡ) antagonist, KN93 (HNK). The HF mice was prepared using left anterior descending coronary artery ligation. As animal model preparation, the heart function was detected using echocardiography. H&E and MASSON trichrome staining were performed to identify myocardial injury; The apoptosis of myocardial was examined by TUNEL staining assay. The levels of different oxidative stress-related proteins were measured through ELISA assay ; The reactive oxygen species and Nrf2 expression in heart tissue were observed with immunofluorescence assay. The levels of SERCA2a, calmodulin, endoplasmic reticulum stress regulatory protein and Nrf2/HO-1 protein were measured using western blotting. ResultsThe results demonstrated that NBP can significantly promote heart function, relieve the injury and inhibit cell apoptosis, meanwhile, reduce ERS injury in heart failure mice through increasing SERCA2a level and reducing Ca2+ influx. Finally, NBP was demonstrated to reduce CaMKⅡphosphorylation levels and decrease cAMP-response element binding protein phosphorylation levels, which suggested that NBP could also activate Nrf2/HO-1 signaling pathway. ConclusionsThis study identified that NPBs treatment promotes the cardiomyocytes ERS and alleviates myocardial injury in heart failure mice which is related with stimulating Nrf2/HO-1 signaling pathway, regulating Ca2+-SERCA2a and reducing Ca2+ influx.
Identification of CFHR4 Associated With Poor Prognosis of Hepatocellular Carcinoma
Authors: DING Qinglin , XU Zhigao , LI Hanluo , HU Kanghong , YE Qifa
Published: September 2021

Background: Hepatocellular carcinoma (HCC) is one of the most leading causes of cancer death worldwide. The 5-year survival rate of HCC patients remains low due to the lack of early-stage symptoms. Human complement factor H-associated protein 4 (CFHR4) is a critical gene that belongs to the factor H family of plasma glycoproteins, which has not been linked to HCC development. The correlations between CFHR4 and prognosis and tumor-infiltrating lymphocytes in HCC are yet unknown. The present study demonstrated the involvement of CFHR4 in HCC via data mining approaches. Results: A total of 18 upregulated and 67 down-regulated DEGs were identified. Importantly, CFHR4, which was screened from DEGs, was shown to express at a lower level in HCC tumor tissue than normal tissues. Western blotting (WB) and immunohistochemical (IHC) experiments of clinical samples further validated CFHR4 was aberrantly expressed in HCC patients; Data from TCGA showed that CFHR4 was inversely correlated with a cancer family history, histological grade, tumor node metastasis (TNM） stage, and serum AFP level of HCC patients; Univariate and multivariate analyses revealed that low expression of CFHR4 was an independent predictive marker in patients with HCC; Kaplan-Meier analysis showed that the lower expression of CFHR4 was significantly associated with the progression of HCC and poor prognosis rates. Furthermore, TIMER analysis indicated that CFHR4 expression levels had correlations with infiltrating levels of immune cells in HCC.Conclusion: CFHR4 expression was low in HCC and was significantly related to the poor prognosis of HCC and the level of immune infiltration. CFHR4 played important roles in regulating the initiation and progression of HCC and could be a potential biomarker for the diagnosis and prognosis of HCC. Methods: The expression of CFHR4 was analyzed by GEO and TCGA-LIHC database and verified by WB and IHC assay. The biological function of CFHR4 was performed by GO and KEGG enrichment analysis, and the genomic alteration of CFHR4 was investigated by cBioPortal database.The correlation between CFHR4 expression and clinical relevance was evaluated through Cox proportional hazards model, and the correlation between CFHR4 expression and tumor immune infiltrates were studied by TIMER database.
Glutathione Peroxidase 3 (GPX3) Expression Predicts the Prognosis of Numerous Malignant Tumors: A Pan-Cancer Analysis
Authors: Wang Yuetong , Fu Guotao , Chen Xueqin , Xia Zengrun , Qi Meng , Du Xiaoping , Liu Kun , Liu Qiling , Sun Na , Shi Chuandao , Zhang Rongqiang , Qu Kai
Published: September 2021

Background: Malignant tumor is a general term for uncontrollable growth of cells. Several studies have investigated that role of GPX3 in tumors. However, no pan-cancer analysis has be conducted to assess the diagnostic and prognostic potential of GPX3. Methods: GPX3 mRNA and protein expression profile was analyzed in the TCGA+GTEx database and CPTAC database. Kaplan-Meier survival curves and forest plots were constructed to help evaluate the impact of GPX3 on the survival and prognosis of cancer patients. Gene mutations of GPX3 were analyzed based on TMB/MSI. The correlation between GPX3 and tumor immune infiltration was assessed using TIMER2. Enrichment analysis was performed to determine tumor-related signaling pathways associated with GPX3. A prediction model for STAD was established. Results: GPX3 was downregulated in most malignant tumors, and was significantly associated with the survival and prognosis of malignant tumors, such as STAD, PAAD, COAD, etc. Moreover, GPX3 expression was positively correlated and negatively with MSI in 13 and 20 categories of tumor respectively after GPX3 expression was positively correlated and negatively with TMB in 9 and 24 tumors separately (P<0.05). A positive correlation was found between GPX3 and the infiltration level of major immune cells and Cancer-associated fibroblasts (P<0.05). The effects of GPX3 were mediated by the AMPK signaling pathway, fructose and mannose metabolism. Conclusions: This is a novel pan-cancer analysis on the relationship between GPX3 and human tumors. Findings of this research will deepen our understanding on the role of GPX3 in the development, regulation and prognosis of malignant tumors.