bluuebunny/crossref_metadata_2025 huggingface dataset:
Obtaining Zonal Isolation in Geothermal Wells
Authors: Rachimillah Allam Putra , Azwar Cinto , Johri Ambuj , Osman Ahmed , Tanoto Eric
Published: June 2021

Cementing is one of the sequences in the drilling operations to isolate different geological zones and provide integrity for the life of the well. As compared with oil and gas wells, geothermal wells have unique challenges for cementing operations. Robust cementing design and appropriate best practices during the cementing operations are needed to achieve cementing objectives in geothermal wells.

Primary cementing in geothermal wells generally relies on a few conventional methods: long string, liner-tieback, and two-stage methods. Each has challenges for primary cementing that will be analyzed, compared, and discussed in detail.

Geothermal wells pose challenges of low fracture gradients and massive lost circulation due to numerous fractures, which often lead to a need for remedial cementing jobs such as squeeze cementing and lost circulation plugs. Special considerations for remedial cementing in geothermal wells are also discussed here.

Primary cement design is critical to ensure long-term integrity of a geothermal well. The cement sheath must be able to withstand pressure and temperature cycles when steam is produced and resist corrosive reservoir fluids due to the presence of H2S and CO2. Any fluid trapped within the casing-casing annulus poses a risk of casing collapse due to expansion under high temperatures encountered during the production phase. With the high heating rate of the geothermal well, temperature prediction plays an important part in cement design. Free fluid sensitivity test and centralizer selection also play an important role in avoiding mud channeling as well as preventing the development of fluid pockets. Analysis and comparison of every method is described in detail to enable readers to choose the best approach.

Massive lost circulation is very common in surface and intermediate sections of geothermal wells. On numerous occasions, treatment with conventional lost-circulation material (LCM) was unable to cure the losses, resulting in the placement of multiple cement plugs. An improved lost circulation plug design and execution method are introduced to control massive losses in a geothermal environment. In addition, the paper will present operational best practices and lessons learned from the authors’ experience with cementing in geothermal wells in Indonesia.

Geothermal wells can be constructed in different ways by different operators. In light of this, an analysis of different cementing approaches has been conducted to ensure robust cement design and a fit-for-purpose cementing method. This paper will discuss the cementing design, equipment, recommendations, and best available practices for excellence in operational execution to achieve optimal long-life zonal isolation for a geothermal well.
Integrated Workflow for Feasibility Study of Cuttings Reinjection Based on 3D Geomechanics Analysis and Case Study
Authors: Shen Xinpu
Published: June 2021

This paper presents an integrated workflow for feasibility study of cuttings reinjection (CRI) based on 3D geomechanics analysis. Solutions of various mechanical variables obtained with 3D geomechanics analysis at various level of scale are used as basis for designing parameters of CRI. Solutions of geomechanics analysis provide basis for a feasibility study and/or design of CRI: solution of 3D geostress distribution and the effective stress ratio are the essential factors for selecting the best location of injection well; solution of 1D geomechanics analysis provides basis for choice of true vertical depth (TVD) interval for injection sections; and hydraulic fracturing performed in the framework of 3D geomechanics analysis provides the most accurate solution for both the injection pressure window and fault reactivation related to CRI as well as estimation of seismic behavior. Example of feasibility study of cuttings reinjection with the integrated workflow proposed here is presented with data from a case in offshore West Africa. Solutions of geomechanics analysis are used for decision making at various stages of CRI. There are several faults in this region. The location of the injection well is chosen at a place with principal stress ratio's value at 0.68. The interval of injection well section is chosen as a 140-ft section with center at TVD = 6,700 ft. The numerical solution of injection pressure window is defined with 46 MPa as lower bound and 80 MPa as upper bound. The width of the fracture is 0.069 m, and length and height are 4,000 m and 100 m respectively. The accommodation volume of fluid with cuttings is 2.76×104 m3. The maximum magnitude of Richter scale of the seismicity corresponding to the fault reactivation is 3.15. The case study described in this paper provides an integrated workflow for feasibility study of CRI based on 3D geomechanics analysis. A best practice for this type of CRI design is also presented.
Use Of Fiber Materials to Mitigate Lost Circulation During Cementing Operations in Turkmenistan
Authors: Bugrayev Amanmammet , Nafikova Svetlana , Taoutaou Salim , Gurbanov Guvanch , Hanov Maksatmyrat , Rathod Vishal
Published: June 2021

Lost circulation in depleted sands during a primary cementing job is a serious problem in Turkmenistan. The uncertainty in formation pressure across these sands increases the risk of losses during drilling and cementing, which results in remedial operations and nonproductive time. The need to find a fit-for-purpose lost circulation solution becomes even more critical in an environment with narrow pore pressure-to-fracture gradient, where each cement job with losses compromises the downhole well integrity.

An engineered lost circulation solution using innovative materials in the cement slurry was carefully assessed and qualified in the laboratory for each case to optimize the formulation. The lost circulation control treatment combines specialized engineered fibers with sized bridging materials to increase the effectiveness of treatment, formulated and added to the cement slurries based on the slurry solids volume fraction (SVF). Cement slurries with low SVF were treated with higher concentrations of the product and slurries with high SVF used lower concentrations.

More than 50 jobs were performed with cement slurries designed at various densities and SVF up to 58% and using this advanced lost circulation material (LCM) to mitigate losses during cementing. Field experience showed positive results, where the differential pressure up to 2,800 psi was expected during cementing operation. A local database, generated based on the design and development work performed, enabled improved decision-making for selection and LCM application requirements for subsequent jobs and development of a lost circulation strategy. The mitigation plan was put in place against losses in critical sections and depleted sand formations in Turkmenistan. It assisted in meeting the cement coverage requirements on numerous occasions, improving overall the integrity of the wells and thus, was considered to be a success.

This paper provides insight of this advanced LCM, its application in cement slurries, the logic behind the developed loss circulation strategy, and the high success rate of its implementation. Three case histories are presented to demonstrate the strategy and results.
Best Practice of Bit Optimization in a Strong Heterogeneity Conglomeratic Sandstone Reservoir: 8 Years Case History from Juggar Basin, West China
Authors: Ma Jing , Yu Guijian , Wang Chengcheng , Jin Xiaowei , Zang Chuanzhen , Li Qing , Wang Hongtao , Chen Naizhi , Sun Jianwei , Zhou Diao , Gao Jiji , Wares Annie , Wang Yong , Gjertsen Ole , Li Tong , Lan Wencheng
Published: June 2021

MH oilfield, located in the Junggar Basin, in Xin Jiang Province of northwest China, is the world largest conglomerate reservoir with a fan-delta sedimentary environment. This long-term project can be traced back to 2012, and since then has gone through many technology revolutions and optimizations. At the end of 2017, the drilling performance of one main block inside MH oilfield, M18, was not optimistic when compared with other blocks. The extremely high formation hetergenity of the field made it very challenging to choose the right bit at the right time. This long-term project has brought to light the dedicated, quantifying study of the rock property differences throughout this field and inside each block. To solve this tough bit selection problem, geologic data was interpreted for engineering use. Two lines of data were processed. One was offset analysis based on the current run records to optimize bit designs, and the other was rock property interpretation and simulation to predict the formation variation, which covers the unconfined compressive strength (UCS), confined compressive strength (CCS) abrasion, impact simulations, layer correlations, statistical analysis and contour mappings of interest zones.

This paper will summarize the field history, delineate the bit design lineage in this long-term project, and then mainly focus on geology simulations. The objective of this paper is bring to light the importance of CCS simulations to predict the bit performance and help the bit design and selection; provide a bit design lineage and bit optimization workflow for the drilling operation to optimize the inventory utilization and streamline the decision-making loop; provide a case study with coordinating multiple disciplinary teams to achieve specified objective; and provide a concept of integration of geology and engineering in the world largest conglomerate reservoir.
Well Design and Engineering Process Automation
Authors: Kiani Nassab Kazem , Garg Rachit , Benjaboonyazit Veerawit , Harianto Rudy , Ur Rehman Atiq , Durongwattana Nithipoom , Buapha Sompop
Published: June 2021

Drilling engineers use several applications to perform well design tasks and to create a final report for review and approval, any changes in subsurface information require revalidation of engineering calculations and repeat of the entire tasks to update the stage-gate report. This is usually a manual, timeconsuming and human error prone process that may result in additional cost and/or prolonged planning cycle time. Moreover, such manual works by individual engineers lead to diversified well design practices and formats across a company which make it difficult for standardization and compliance control.

Drilling engineering computer programs are primarily standalone applications that are used for engineering calculations with no continuous workflow in most cases. Well Delivery Process (WDP) is an engineering software solution developed to integrate, automate and standardize well construction planning process across the operating company. The system encompasses several integrated workflows by which users can carry out drilling/completion tasks from feasibility study to concept selection and detailed design as well as operations monitoring and closeout reports on a single digital platform. Furthermore, functions such as engineering calculations, rules validation, offset analyzing, well schematic, risk analysis, checklist, and well program are automated through the workflows and several microservices built on a series of applications.

The WDP, based on the company's well design automation initiative, was developed jointly with the service provider using its Business Process Management (BPM) tools. The system integration transforms how wells are constructed and delivered by combining a digitalized planning and design process with engineering models on a single and open cloud-native platform. Several tools and techniques such as design templates, continuous calculations, well cost models, etc. are utilized through integrated workflows to automate well design and process. The solution supports all new wells and leverage data from existing wells to optimize well construction process. As a result, the collaborative well design platform and automation tools take the drilling engineering process to the next level with a better quality well design and a reduced planning time.
Directed evolution improves the enzymatic synthesis of L-5-hydroxytryptophan by an engineered tryptophan synthase
Authors: Lisheng Xu , Li Tingting , Huo Ziyue , Chen Qiong , Xia Qiuxia , Jiang Bianling
Published: June 2021

L-5-Hydroxytryptophan is an important amino acid that is widely used in food and medicine. In this study, L-5-hydroxytryptophan was synthesized by a modified tryptophan synthase. A direct evolution strategy was applied to engineer tryptophan synthase from Escherichia coli to improve the efficiency of L-5-hydroxytryptophan synthesis. Tryptophan synthase was modified by error-prone PCR. A high activity mutant enzyme (V231A/K382G) was obtained by a high-throughput screening method. The activity of mutant enzyme (V231A/K382G) is 3.79 times higher than that of its parent, and kcat/Km of the mutant enzyme (V231A/K382G) was 4.36 mM− 1∙s− 1. The mutant enzyme (V231A/K382G) reaction conditions for the production of L-5-hydroxytryptophan were 100 mmol/L L-serine at pH 8.5 and 35°C for 15 h, reaching a yield of L-5-hydroxytryptophan of 86.7%. Directed evolution is an effective strategy to increase the activity of tryptophan synthase.
Research on Multiphysics Coupling Fields in Electrochemical Trepanning of Lateral Flow
Authors: Lei Gaopan , Zhu Dong , Zhu Di
Published: June 2021

Electrochemical trepanning (ECTr) is an effective method for machining the ruled surface parts. Generally, the forward flow mode is used in ECTr. Under the forward flow, the streamlines at the outlet are divergent, resulting in the obvious flow patterns at the outlet and the instability of the machining process. In ECTr of a diffuser with a special structure, the lateral flow mode is adopted to improve the uniformity of the flow field, thereby improving the surface quality at the hub. ECTr is a complicated multiphysics coupling process. To investigate the distributions of electric field, two-phase flow field and thermal field in ECTr with lateral flow, a multiphysics coupling field model was established. In this model, a coupling relationship was formed between the various physical fields through the change of the electrolyte conductivity. Through the multiphysics coupling simulation, the changes of the gas bubbles volume fraction, the electrolyte temperature, the electrolyte conductivity and the current density were obtained along the flow path. Compared with the inlet of the electrolyte, the gas bubbles volume fraction and the temperature at the outlet increased by 38.8% and 6.3 K, respectively. Under the combined influence, the conductivity decreased by 7.227 S/m at the outlet, resulting in a decrease of 57.81 A/cm2 in the current density. Then, the corresponding experiment of lateral flow ECTr was performed to verify the simulation results. Along the flow path, the thickness of the machined blade gradually increased, varying from 2.09 mm to 2.76 mm. The surface quality gradually deteriorated along the flow path and the surface roughness varied from Ra 0.72 μm to Ra 1.05 μm. Combining the simulation and the experiment, the correctness and the effectiveness of the multiphysics coupling model and simulation were confirmed. The results can be applied to other ECM processes.
Energy Efficient Cluster based Routing Protocol for WSN based on Hybrid BSO-TLBO Optimization Model
Authors: Priya J Sathya , Alenazy Wael Mohammad , Sathyabama A R
Published: June 2021

The most famous Wireless Sensor Networks (WSN) is one of the cheapest and rapidly evolving networks in modern communication. It can be used to sense various substantial and environmental specifications by providing cost-effective sensor devices. The development of these sensor networks is exploited to provide an energy-efficient weighted clustering method to increase the lifespan of the network. We propose a novel energy-efficient method which utilizes the Brainstorm algorithm in order to adopt the ideal CH to reduce energy-draining. Further, the effectiveness of the Brain Storm Optimization (BSO) algorithm is enhanced with the incorporation of the Modified Teacher-Learner Optimized (MTLBO) algorithm with it. The modified BSO-MTLBO algorithm can be used to attain an improved throughput, network lifetime, and to reduce the energy consumption by nodes and CH, death of sensor nodes, routing overhead. The performance of our proposed work is analyzed with other existing approaches and inference that our approach performs better than all the other approaches.
Effect of Organic Loading Rate on the Biological Performance of the Thermophilic Anaerobic Membrane Bioreactor Treating Pulp and Paper Primary Sludge
Authors: Bokhary Alnour , Leitch Mathew , Liao Baoqiang
Published: June 2021

Waste-to-energy or value-added products have been increasingly considered in many pulp and paper mills (PPMs) worldwide. However, developing appropriate conversion technologies is a major challenge in transforming PPMs wastes into biofuels or value-added biomaterials. In the present study, a long-term (320 d) anaerobic digestion of primary sludge of a thermomechanical pulp mill (TMP) was carried out for the first time in a thermophilic anaerobic membrane bioreactor (ThAnMBR). Effect of organic loading rate (OLR) in the range of 2.5–6.8 kg-COD/m3 d and hydraulic retention times (HRT) of 3–8 d on the process performance was investigated. Under various OLRs, stable biogas productions were obtained, and the best results were achieved with lower OLR (2.5 kg-COD/m3 d) and higher HRT (8 d), at biogas yields of 189 L biogas/kg MLSS fed. However, it was found that biogas production and sludge biomass degradation decrease when the organic loading rate increases. The proportion of sludge reduction ranged from 28.9 to 46.7% depending on the applied OLRs. Despite varying OLRs, stable membrane performance was obtained, where the required membrane flux was easily maintained during the reactor operation. In this study, also the properties of digestate and membrane permeates were studied under different operating conditions, and they fluctuated to some extent with OLR. ThAnMBR is a promising new technology for pulp and paper mill primary sludge treatment.
Upgrading an Analog Recovery Loop for Optimized Decoding Jointly to an Increased data-Rate
Authors: Visalli Giuseppe
Published: June 2021

The maximum likelihood detection theory improves the error-rate of a sub-optimal but cheaper, coded symbol recovery loop using oversampling proposed as an alternate solution for the decoding problem without the log-likelihood ratio computation. The former implementation delivers the output data in one-symbol delay, and the required transistor count makes this approach attractive for ultra-low-energy wireless applications. The proposed hardware upgrade includes an analog to digital converter and fixed-point accumulation logic to compute the soft values, replacing a trigger used as a hard detector. This work investigates the soft decoding in the presence of binary and non-binary source symbols. Simulation results show that the soft approach improves the signal-to-noise ratio by 3dB and 2.5 dB when the encoding rates are 1/3 and 2/3.
Assessment of the Association of HIV Infection with Hepatic Steatosis or Fibrosis: a Cross-Sectional, Case-Control Study
Authors: Debroy Paula , Nagraj Sanjana , Chamorro-Pareja Natalia , Castro Neva , de Leon Alejandro , Guerson-Gil Arcelia , Quintero Orlando , Laniado Isaac , Kladas Michael , Desai Dimpi , Mathias Priyanka , Leider Jason , Kishore Preeti , Palaiodimos Leonidas , Kotler Donald P
Published: June 2021

Background: Human immunodeficiency virus (HIV) infection and antiretroviral therapy have been associated with non-alcoholic fatty liver disease (NAFLD), but few studies have evaluated whether HIV infection is an independent risk factor for the development of hepatic steatosis and advanced liver fibrosis. Objectives: To study the prevalence and severity of hepatic steatosis and advanced fibrosis in people living with HIV and control outpatients. Methods: We conducted a cross-sectional analysis of relevant data from 875 pairs of individuals belonging to an HIV-dedicated outpatient clinic and an adult primary care clinic of an inner-city hospital. Hepatic Steatosis Index (HSI) and FIB-4 index were calculated as non-invasive measures of steatosis and fibrosis, respectively. A multivariate logistic regression analysis was performed to assess predictors of steatosis and advanced fibrosis. Results: The prevalence of hepatic steatosis, determined by HSI ≥36, was higher in HIV-negative subjects (71.5% vs. 65.4%, p=0.006). The prevalence of advanced fibrosis, determined by FIB-4 index ≥3.25, was higher in the HIV-positive group (7% vs. 1.7%, p <0.001). Multivariable analysis did not identify HIV infection to be an independent risk factor for hepatic steatosis (p=0.068) and advanced fibrosis. Conclusions: In this cohort, hepatic steatosis was more prevalent in non-HIV infected patients, while advanced fibrosis had a higher prevalence in people living with HIV. HIV infection was not found to be an independent risk factor for either hepatic steatosis or fibrosis.
Effect of faying surfaces and characterization of aluminium AA6063-steel AISI304L Dissimilar joints fabricated by friction welding with Hemispherical Bowl, and Threaded Faying Surfaces
Authors: Subramanian Senthil Murugan , Paulraj Sathiya , Haq Noorul Haq Abdul
Published: June 2021

This work describes the effect of newly introduced faying surfaces on the microstructure and the mechanical properties of dissimilar weld joints of AA6063 and AISI304L alloys that fabricated through the rotary friction welding process (RFW). The experiments were done as six different experimental methods (‘A’ to ‘F’) at 1300 rpm rotation, 18 MPa friction pressure (FP), 24 MPa upset pressure (UP) and 5 sec friction time (FT) with the faying surfaces of hemispherical bowl and thread of 1 mm pitch on the weld specimens. The fabricated joints and the weld zones were characterized by macro and micro-study, Energy Dispersive X-ray Spectroscopy (EDS) spectrums, tensile properties, Vickers microhardness, impact toughness and fractography. The results showed that these faying surface modifications strengthen the bonding between the weld specimens and influences the performance of the joints. The hemispherical bowl showed better results than the threaded surfaces. Axial shortenings were within the acceptable limit in the range of 20–27 mm. Macro and microstructural studies showed the defect-free weld joints and the strong bonding between AA6063 and AISI304L alloys. The hemispherical faying surface on AISI304L alloy formed a U-shaped weld interface (WI) in the dissimilar joints. EDS proved the formation of the Fe-Al intermetallic and the element ‘O’ at weld zone. The joint efficiency for all the methods was around ≥ 100%. Maximum tensile strength was recorded as 238 MPa for method ‘F’. The threaded surface showed good hardness property nearby WI and method ‘A’ yielded maximum impact toughness for the joint.
Global Longitudinal Strain in Heart Transplantation Recipients Using Different Vendors: Reliability and Validity in a Tertiary Hospital in Colombia.
Authors: Fernandez Oscar Mauricio Perez , Medina Hector M. , López Mónica , Barrera Madeleine , Martinez Azucena , Benavides Jhonattan , Duran Juan C. , Salazar Gabriel , Manrique Frida Tatiana
Published: June 2021

Global Longitudinal Strain (GLS) is a useful tool to follow-up heart transplant (HT) recipients. Important inter-vendor variability of GLS measurements has been reported in healthy subjects and different conditions, but there is still limited evidence among HT patients. We assessed the reliability and validity of GLS using two vendors (General Electric and Philips) in a group of consecutive and stable adult HT recipients. Patients underwent two concurrent GLS analyses during their echocardiographic follow-up. We evaluated GLS inter-vendor reliability using Bland-Altman’s limits of agreement (LOA) plots, computing its coverage probability (CP) and the intraclass correlation coefficient (ICC). Validity was assessed though receiver operating characteristics (ROC) curves, predictive values, sensitivity and specificity of GLS for each vendor to detect a normal left ventricle function. 78 pairs of GLS studies in 53 stable HT patients were analyzed. We observed a modest inter-vendor reliability with a broad LOA (less than 50% of values falling out our CP of 2% and an ICC of 0.49). ROC analyses (areas under the curve of 0.824 Vs. 0.631, p<0.05) and diagnosis test indices (Sensitivity of 0.73 Vs. 0.64; and Specificity of 0.79 Vs. 0.50) favored GE over Philips. Inter-vendor variability for GLS analysis exceeded clinically acceptable limits in HT recipients. GLS from GE software seemed to show higher validity as compared to Philips’. The present study provides evidence to consider caution for the interpretation of GLS for clinical management in the follow-up of HT patients, especially when GLS is measured by different vendors.
Four-Factor Prothrombin Complex Concentrate to Reduce Post-Traumatic Hemorrhage in Patients with Major Trauma, the PROCOAG Trial: Study Protocol for a Randomized Multicenter Double-Blind Superiority Study
Authors: Bouzat Pierre , Bosson Jean-Luc , David Jean-Stéphane , Riou Bruno , Duranteau Jacques , Payen Jean-François
Published: June 2021

Background: Optimal management of severe trauma patients with active hemorrhage relies on adequate initial resuscitation. Early administration of coagulation factors improves post-traumatic coagulation disorders and four-factor prothrombin complex concentrate (PCC) might be useful in this context. Our main hypothesis is that four-factor PCC in addition to a massive transfusion protocol decrease blood product consumption at day one in severe trauma patients with major bleeding.Methods This is a prospective, randomized, multicenter, double-blind, parallel, controlled superiority trial. Eligible patients are trauma patients with major bleeding admitted to a French level-I trauma centre. Patients randomized in the treatment arm receive 1 mL/kg four-factor PCC within one-hour post-admission while patients randomized in the controlled group receive 1 mL/kg of saline solution 0.9% as a placebo. The primary endpoint is the amount of blood products transfused in the first 24 hours post-admission (including red blood cells, frozen fresh plasma and platelets). The secondary endpoints are the amount of each blood product transfused in the first 24 hours, time to achieve prothrombin time ratio < 1.5, time to hemostasis, number of thrombo-embolic events at 28 days, mortality at 24 hours and 28 days, number of intensive care unit (ICU)-free days, number of ventilator-free days during ICU stay, number of hospital-free days within the first 28 days, hospitalization status at day 28, Glasgow outcome scale extended for patients with brain lesions on initial cerebral imaging, and cost of each strategy at day 8 and 28. Inclusions have started in December 2017 and are expected to be complete by June 2021. Discussion: If PCC reduces total blood consumption at day one after severe trauma, this therapy, in adjunction to a classic massive transfusion protocol, may be used empirically on admission in patients at risk of massive transfusion to enhance coagulation. Moreover, this treatment may decrease blood product related complications and may improve clinical outcome after post-traumatic hemorrhage. Trial registration: This study has been prospectively registered on clinical trial on July 14, 2017 NCT03218722
Lung Ultrasound in COVID-19: Clinical Correlates and Comparison With Chest Computed Tomography
Authors: Portale Grazia , Ciolina Federica , Arcari Luca , Giraldi Gianluca Di Lazzaro , Danti Massimiliano , Pietropaolo Lorenzo , Camastra Giovanni , Cordischi Chiara , Urbani Laura , Proietti Lidia , Cacciotti Luca , Santini Claudio , Melandri Serena , Ansalone Gerardo , Sbarbati Stefano , Sighieri Cinzia
Published: June 2021

Background: lung ultrasound (LUS) and chest computed tomography (chest-CT) are largely employed to evaluate coronavirus-disease-19 (COVID-19) pneumonia. We investigated semi-quantitative LUS and CT scoring in hospitalized COVID-19 patients.Methods: LUS and chest-CT were performed within 24 hours upon admission. Both were analyzed according to semi-quantitative scoring systems. Subgroups were identified according to median LUS score.Results: patients within higher LUS-score group were older (79 vs 60 years, p<0.001), had higher C-reactive protein (CRP) (7.2 vs 1.3 mg/dl, p<0.001) and chest-CT score (10 vs 4, p=0.027) as well as lower PaO2/FiO2 (286 vs 356, p=0.029) as compared to patients within lower scores. We found a significant correlation between scores (r=0.390, p=0.023). Both LUS and CT scores correlated directly with patients age (r=0.586, p<0.001 and r=0.399, p=0.021 respectively) and CRP (r=0.472, p=0.002 and r=0.518, p=0.002 respectively), inversely with PaO2/FiO2 (r=-0.485, p=0.003 and r=-0.440, p=0.017 respectively). LUS-score only showed significant correlation with hs-Troponin T, NT-pro-BNP and creatinine (r=0.433, p=0.019; r=0.411, p=0.027 and r=0.497, p=0.001 respectively).Conclusions: semi-quantitative bedside LUS related to the severity of COVID-19 pneumonia similarly to chest-CT. Correlation of LUS-score with markers of cardiac and renal injury suggests that LUS might contribute to a more comprehensive evaluation of this heterogeneous population.
Simple Positivity Preserving Nonlinear Finite Volume Scheme for Subdiffusion Equations on General Non-conforming Distorted Meshes
Authors: Yang Xuehua , Zhang Haixiang , Zhang Qi , Yuan Guangwei
Published: June 2021

We propose a positivity preserving finite volume scheme on non-conforming quadrilateral distorted meshes with hanging nodes for subdiffusion equations, where the differential equations have a sum of time-fractional derivatives of different orders, and the typical solutions of the problem have a weak singularity at the initial time t =0 for given smooth data. In this paper, a positivity-preserving nonlinear method with centered unknowns is obtained by the two point flux technique, where a new method to handling vertex-unknown including hanging nodes is the highlight of our paper. For each time derivative, we apply the L1 scheme on a temporal graded mesh. Especially, the existence of a solution is strictly proved for the nonlinear system by applying the Brouwer’s fixed point theorem. Numerical results show that the proposed positivity-preserving method is effective for strongly anisotropic and heterogeneous full tensor subdiffusion coefficient problems.
Self-Efficacy Mediates The Relationship Between Social Support And Psychological Resilience In Patients With Lung Cancer: A Cross-Sectional Study
Authors: Yin Yizhen , Zhang Jie , Lv Mengmemg , Li Hui , Li Huiyuan , Zhang Jingping
Published: June 2021

Purpose: The prognosis of patients with lung cancer might be influenced by mental health. Psychological resilience is one of the important indicators to reflect the psychological state. It has been shown that patients with higher social support and self-efficacy have better psychological resilience. The aim of this study was to determine whether or not self-efficacy mediates the relationship between social support and psychological resilience in patients with lung cancer.Methods: A cross-sectional study of 303 lung cancer patients was conducted. Participants completed questionnaires, including the Chinese version of the Perceived Social Support Seale Scale, the Chinese version of Strategies Used by People to Promote Health Scale, and the Chinese version of the Connor-Davidson Resilience Scale. Results: Mediation analysis indicated that self-efficacy had a partially mediating effect between social support and psychological resilience. Direct paths from social support to self-efficacy, self-efficacy to psychological resilience, and social support to psychological resilience were significant (p< 0.001). Moreover, indirect paths from social support to self-efficacy and self-efficacy to psychological resilience were also significant at the 95% level [0.120–0.550]; the mediating effect accounted for 38.16% of the total effect.Conclusions: Self-efficacy plays an important role in the relationships between social support and psychological resilience in cancer patients. Social support not only directly influenced the psychological resilience, but also indirectly influenced psychological resilience through self-efficacy.
Downregulation of AnnexinA5 Gene Expression in Coronary In-Stent Restenosis – A Pilot Study
Authors: Baktashian Mojtaba , Soflaei Sara Saffar , Salehi Mansoor , Moohebati Mohsen , Iravani Omid , Moghadam Mahsa Rastegar , Pasdar Alireza , Ghayour-Mobarhan Majid , Hashemi Mohammad
Published: June 2021

Background and aims:

In- stent restenosis (ISR) is the Achilles heel of angioplasty. AnnexinA5 as an anticoagulant has been shown have anti-inflammatory and anti-atherosclerotic effects. Here we aim to investigating the mRNA expression of AnnexinA5 in peripheral white blood cell of patients with in-stent restenosis.
Methods

Patients with the history of coronary stent implantation who candidate for re-angiography were entered the study and allocated into two groups according the results of re-angiography; in-stent restenosis (stenosis ≥ 50% in stent) and non-in-stent restenosis (stenosis < 50% in stent). Total RNA of WBC was extracted and cDNA was synthesized using commercial kits. AnnexinA5 expression was assessed with real time PCR and TaqMan probe and reported in relation with GAPDH as a housekeeping gene.
Result

AnnexinA5 expression was investigated in total 50 participants including 25 ISR and 25 non-ISR. Baseline characteristics including age, sex, smoking habits, hypertension, diabetes mellitus, dyslipidemia and stent in LAD were statistically the same in cases and controls. AnnexinA5 expression in ISR patients was 50% lower than controls.
Conclusion

AnnexinA5 is down-regulated in ISR and could be considered as a biomarker for predicting ISR and furthermore it could be used as prevention for ISR occurrence.
MiR-224 Promotes Lymphatic Metastasis by Targeting ANGPTL1 in Non-Small-Cell Lung Carcinoma
Authors: Han Haibo , Pan Bo , Liang Fan , Wu Lina , Liu Xijuan , Yang Yue , Chen Jin-feng
Published: June 2021

Background: MicroRNAs can regulates tumor metastasis either as an oncomiR or suppressor miRNA. Here, we investigate the role of miR-224 in lymphatic metastasis of non-small-cell lung cancer (NSCLC). Methods: The expression of miR-224 was demonstrated by a validation cohort of 156 lung cancer patients (77 cases with lymphatic metastasis) by q-PCR. In vitro and in vivo experiments were performed to study the malignant phenotype after upregulation and inhibition of miR-224 expression. Furthermore, the direct target genes of miR-224 were determined by a luciferase reporter assay. Results: miR-224 was identified as a high expression miRNA in the tumor tissues with lymphatic metastasis) with an area under the receiver operating characteristic curve (AUC) of 0.57. Forced expression of miR-224 in H1299 cells promoted not only the cell viability, plate clone formation, migration and invasion in vitro, but also tumor growth and lung metastasis in vivo. Consistently, inhibition of miR-224 suppressed the malignant characters both in vitro and in vivo. Molecular mechanism research suggested that miR-422a targeted the ANGPTL1 as a novel tumor suppressor.Conclusions: The present study demonstrates that miR-224 is a potential marker for the prediction of lymphatic metastasis of NSCLC. And application of miR-224 may help for prophylactic intervention of NSCLC in clinical practice.
Epigenetic Programming during thymic development sets the stage for optimal
function in effector T cells via DNA demethylation
Authors: Issuree Priya , Teghanemt Athmane , Pulipati Priyanjali , Day Kenneth , Yorek Matt , Yi Ren , Misel-Wuchter Kara , Keen Henry , Au Christy , Maretzky Thorsten , Gurung Prajwal , Littman Dan
Published: June 2021

The potential for early thymic developmental events to program epigenetic states that influence adult T cell physiology remains an important question in health. Herein using the Cd4 locus as a paradigm for early developmental programming, we demonstrate that DNA demethylation during thymic development is critical for the licensing of a novel stimulus-responsive element that serves to maintain CD4 gene expression in effector T cells. We document the importance of maintaining high CD4 expression during parasitic infection and show that by driving transcription, this stimulus-responsive element allows for the maintenance of H3K4me3 levels during T cell replication, which is critical for repelling de novo DNA methylation at the Cd4 promoter. A failure to undergo epigenetic programming during development leads to gene silencing during effector T cell replication, thus providing evidence that early development can program stimulus-responsive elements to propagate a stable epigenetic state in effector T cells, with important biological consequences.
Investigation of Symptom Status, Body Perception Levels and Symptoms of Anxiety and Depression in Breast Cancer Patients Receiving Paclitaxel: A Prospective Longitudinal Study
Authors: CEYLAN GAMZE GÖKÇE , METİN Zehra GÖK
Published: June 2021

Purpose: This study aimed to investigate symptom status, body perception level changes and the symptoms of anxiety and depression in breast cancer patients receiving Paclitaxel.Methods: This descriptive, and prospective study was conducted with 84 breast cancer patients receiving paclitaxel regimen. “Chemotherapy Symptom Assessment Scale (C-SAS)”, “Body Perception Scale (BPS)” and “Hospital Anxiety and Depression Scale (HADS)” were applied at five time points (T₁, T₂, T₃, T₄, T₅). Data was analyzed using descriptive statistics, Wilcoxon, Friedman, Cochrane Q and Spearman’s correlation tests.Results: The frequency of needling and numbness in hands and feet, pain, and skin or nail changes significantly increased in the subsequent assessment points (T₂, T₃, T₄, and T₅) compared to the initial assessment (T₁) (p<0.05). The mean scores of BPS significantly decreased at T₂, T₄, and T₅ (p<0.01). The mean scores of the anxiety subscale of the HADS scale decreased at the T2, T3, and T4 (p<0.01), and the mean scores of the depression subscale significantly increased at the T3, T4, and T5 (p<0.01).Conclusions: The findings underscore the need for oncology nurses to provide comprehensive training sessions on effective symptom management, changes in body perception levels, and alleviation of the symptoms of anxiety and depression in breast cancer patients receiving paclitaxel. In this way, the physiological symptom burden that occurs in patients may be alleviated, and negative changes in body perception, anxiety and depression symptoms may be decreased.
Development of a Novel Wireless Multi-Channel Stethograph System for Monitoring Cardiovascular and Cardiopulmonary Diseases
Authors: Zhang Xingzhe , Maddipatla Dinesh , Narakathu Binu B. , Bazuin Bradley J. , Atashbar Massood
Published: June 2021

A multi-channel stethograph system was designed and developed as an electronic auscultation system for graphic recording of heart, lung and trachea (HLT) sounds non-invasively through a set of 16 acoustic sensors. The multi-channel stethograph system was fabricated by placing 16 microphone based acoustic sensor in a CNC machined Delrin® housing cases that are covered using diaphragms. Among the 16 acoustic sensors, 14 were positioned in a memory foam pad and 2 were placed directly on the heart and trachea to acquire sounds simultaneously from the lungs, heart and trachea. The sounds acquired from the 16 acoustic sensors were processed through a custom designed and fabricated 16-channel PCB for signal conditioning. A National Instruments (NI) 9205 data acquisition device (DAQ) along with a NI 9191 wireless chassis was used to acquire and wirelessly transmit the data from the 16-channel PCB to a Wi-Fi enabled device such as a PC/tablet. A custom LabVIEW program was developed on a Wi-Fi enabled PC/tablet to record the data from the DAQ. In addition, a MATLAB program was developed to convert the recorded data from the acoustic sensors into 16 audio files (for audio playback) and plot the waveforms in time and frequency domain as well as spectrogram for visual examination of any abnormal patterns in inhalation and exhalation. This provides critical information on the presence of wheezes, crackles and rhonchi sounds as well as abnormal heartbeat and respiration rate which helps in analyzing the condition of heart and lungs. The graphically displayed HLT sounds will help physicians in the clinical diagnosis and monitoring of lung and heart disorders, particularly chronic obstructive pulmonary disease (COPD), asthma, pneumonia, and congestive heart failure by providing objective evidence.
Simulation and Computational Study of Graphene Oxide Nanocarriers Loaded in the Absorption and Release of the Anticancer Drug of Camptothecin
Authors: Moradi Omid , Mahdavian Leila
Published: June 2021

The structure of nano- graphene oxide, due to its special properties such as hydrophilicity, special surface and suitable biocompatibility, the possibility of high loading of hydrophilic and hydrophobic drugs, has attracted special attention in drug release. In this study, after simulating and optimizing the structure of nano-graphene and then nano-graphene oxide (NGO), it was used to load the anti-cancer drug of camptothecin (CA) in aqueous medium and the optimal conditions for achieving maximum loading efficiency of the drug were investigated. Due to the structure of the drug, there are two forms of lactone ring and carboxylate, which if the lactone ring form is predominant, the effectiveness of the drug is increased, which depends on the pH of environment. The calculated thermodynamic and structural results show that the solubility of the drug in relation to nano-graphene and its lactone ring state are maintained by using nano-graphene oxide. By folic acid as an intermediate in aqueous medium, the drug is released to form of lactone ring and is increased the effectiveness of drug. Lactony is maintained the drug structure and is increased the drug effectiveness. The results show that the presence of the ring in the drug structure and its binding to the mediator of folic acid to nano-graphene oxide is a stabilizing factor of keto tautomer. The calculation of vibrational frequencies show that the presence of folic acid intermediate reduces the vibrational frequency of the hydroxyl group (OH) so that its absorption energy (Ead) is equal to the lowest value 65.24 a.u.
The Role of Fiscal Policy in The Inflation: VAR Analysis of Kazakhstan’s Economy, 2005-2020
Authors: Ybrayev Zhandos
Published: June 2021

The paper analyzes the patterns of dynamic effects of fiscal policy to domestic inflation in the context of a small open economy. Using 4-variable (government spending, fiscal deficit, money stock (M2), and domestic inflation rate) vector autoregression model estimated with quarterly data for Kazakhstan’s economy in the period of 2005Q1-2020Q1. We distinguish between government expenditure on consumption and investment. As a result, we find that a fiscal policy shock have certain positive effects on the inflation rate. In particular, social protection spending adds 1% to the inflation rate in the following four quarters, while the government capital purchases do not produce sizable effect on inflation dynamics even in the longer term horizons. Overall, for the fiscal policy to become inflation-neutral, we suggest several policy recommendations.
Electrochemical Determination of Chloramphenicol in Milk and Eye-drop Using Easily Activated Screen Printed Carbon Electrodes
Authors: Hailu Tesfu , Tessema Merid , Li Yaw-Kuen
Published: June 2021

BackgroundAn analytical method that has fast response with cheap price and simple sample preparation is an ideal technique that the science need. An electrochemical sensor is an analytical method that suit for the above criteria to determine various samples using different electrode material. Providing detection method for chloramphenicol in farm product and drug sample using cheap electrode material is required due to its wide application in farm. ResultIn this study, direct and cost-effective activated SPCE was made electrochemically to determine chloramphenicol in eye-drop and pasteurized milk. The activation of the SPCE was straightforward and done by cycling 0.5 M KOH using LSV techniques. The employed surface imaging, spectroscopy, and electrochemical analysis show that there is an effective formation of new functional groups during the activation. The activated SPCE gave a superb current response for Chloramphenicol during the CV and SWV study using PBS of pH 6.5 compared to that of the bare one. Utilizing the optimal SWV conditions, a linear calibration curve was obtained using the range of 0.05‒100 µM with quite a small detection limit of 20 nM. ConclusionIn general, the higher sensitivity, stability and remarkable recovery results on the real sample analysis indicate that the activated screen printed carbon electrode can be applied to analyses sample in the field cause it have high stability, excellent reproducibility and long-term stability.
Short-Term Canopy and Long-Term Effects Soil of a Native Shrub Under Arid Bioclimate: A Case Study From Tunisia
Authors: Noumi Zouhaier , Mseddi Khalil , Mezghani Imed
Published: June 2021

Interactions between plants (competition and facilitation) in terrestrial ecosystems include: (1) short-term effects primarily quantified with experimental removals; and (2) long-term effects primarily quantified with observational methods. This study, conducted in the National Park of Bou Hedma, examined (1) the relative contributions of short-term canopy and long-term soil effects of a shrub species in explaining differences in biomass, species diversity (richness) and species density of understory plants (i) between shrubs and open areas, (ii) between shrubs and removed shrubs; and (2) the role of grazing in driving changes in direction of short-term and long-term effects in shrub/understory species interactions.Differences in species richness, density and biomass of understorey communities between shrub removed and open areas were mostly due to long-term soil effects, whereas differences beneath shrubs and shrub removed were due to short-term canopy effects, in particular on soil water content.Our study provides the positive effect of savannas shrubs on the understorey vegetation biomass, species density and diversity in arid ecosystems. Additionally, grazing by large herbivores negatively influenced the dynamics of vegetation under an arid bioclimate.