bluuebunny/crossref_metadata_2025 huggingface dataset:
Modeling Foam Displacement with the Local Equilibrium Approximation: Theory and Experiment Verification
Authors: Chen Q. , Gerritsen M. G. , Kovscek A. R.
Published: September 2008

The gas mobility control aspects of foamed gas make it highly applicable for improved oil recovery. Gas bubble size, often termed as foam texture, determines gas flow behavior. A population balance model has been developed previously for modeling foam texture and flow in porous media. The model incorporates pore-level mechanisms of foam bubble generation, coalescence, and transport. Here, we propose a simplified foam model to reduce computational costs. The formulation is based on the assumption of local equilibrium of foam generation and coalescence and is applicable to high and low quality foams. The proposed foam model is compatible with a standard reservoir simulator. It provides a potentially useful, efficient tool to predict accurately foam flows at the field scale for designing and managing foamed-gas applications.

There are three main contributions of this paper. First, the population balance representation of foam generation by gas-bubble snap off is modified to extend the capability of the population balance approach to predict foam flow behaviors in both the so-called high-quality and low-quality regimes. Second, a simplified population-balance model is developed and implemented with the local-equilibrium approximation. Third, foam displacement experiments in a linear sandstone core are conducted to verify the proposed model. A visualization cell is employed to measure the effluent foam bubble sizes for a transient flow as well as to estimate the in-situ foam bubble sizes along the length of the core during steady flow. Additionally, the evolution of aqueous phase saturation is monitored using X-ray computed tomography (CT) and the pressure profile is measured by a series of pressure taps. Good agreement is found between the experimental results and the predictions of the simplified model, with a minor mismatch in the entrance region.
Equivalent Skin Factors for Nonuniformly Damaged Horizontal and Multilateral Wells
Authors: Yildiz Turhan
Published: September 2008

In the first part of this study, we scrutinize the equivalent skin concept used to emulate the influence of uneven formation damage on the performance of horizontal wells. Rigorous 3D multisegment well models are used to simulate the local changes due to nonuniform formation damage around wellbore accurately. We show that the simple models, presented in the literature, to compute equivalent skin factors are quite limited in their accuracy.

Equivalent skin factor resulting from nonuniform formation damage around a horizontal well, in general, is influenced not only by the static damage distribution itself but also by many reservoir and wellbore variables. A convoluted interaction of well location, distance to reservoir boundaries, reservoir boundary type, formation thickness, well length, extent and nature of static formation damage itself, production time, and the contrast between the flux distributions around damaged and undamaged wells affects and controls the equivalent skin factor around horizontal wells.

In the second part of the study, we investigate the uneven formation damage around multilateral wells. Our investigation concludes that, as far as the equivalent skin factor values are concerned, the multilateral cannot be represented as an extension of horizontal wells. The interaction between the laterals affects the flux distribution around the laterals which in turn influences equivalent skin factors. Commingled production from duallateral systems changes the nature and size of equivalent skin in comparison with equivalent skin factors resulting from individual and separate productions from each lateral. In a duallateral system, the contrast in the individual lateral lengths may have a strong impact on the equivalent skin factors for both laterals.
Smart Chemical Systems for the Stimulation of High-Water-Cut Heavy Oil Wells
Authors: Samir Mohamed Ahmed , Elnashar Islam , Samuel Mathew , Jemmali Mohamed
Published: September 2008

The Nukhul formation in the Gulf of Suez is highly fractured, depleted reservoir producing 9 to 10 API gravity heavy oil at water cuts up to 98%. Stimulation is required to enhance oil production and extend the life of the field. An inherent problem with these wells is poor acid placement during matrix acidizing, especially in reservoirs with high-permeability contrasts. Conventional acidizing results in the stimulation of water zones, and misses targeted oil zones. The high viscosity and low mobility of the Issran field heavy oil, in contrast with the strong mobility and low viscosity of the formation water, makes the problem even more pronounced.

To temporarily plug the water zones and effectively stimulate oil zones with chemical diversion, a new surfactant-based chemistry has been introduced. When mixed in brine, it forms a high viscous gel. The gel maintains its viscosity when contacting water and breaks down when contacting oil, thus temporarily plugging the zones of high water saturation. When mixed in acid, the new system will stimulate and divert automatically based on in-situ gellation mechanism related to acid spending; thus achieving uniform distribution. In addition, the new acid system has a unique inherent property to limit acid penetration in high water saturation zones, while enhancing deeper penetration in high oil saturation layers.

Conventional acid treatments have a low success rate in the Nukhul formation. More than 50% of the stimulated oil wells turned into 100% water producers. The new stimulation treatment fluids and placement techniques improved oil production and lowered WCs. Water cut before acid treatment ranged from 90% to 98%. After the treatment, water cuts lowered to the range from 40% to 75%, and post-oil production increased by as much as three- to eightfold.

This study assesses the performance of the placement techniques and fluids used in the stimulation of the Nukhul formation based on field data. It also quantifies the economical added value resulting from the usage of the surfactant-based systems with respect to conventional matrix stimulation fluids.
The Impact of Gravity Segregation on Multiphase Non-Darcy Flow in Hydraulically Fractured Gas Wells
Authors: Dickins Mark I. , McVay Duane A. , Schubarth Stephen K.
Published: September 2008

Multiphase and non-Darcy flow effects in hydraulically fractured gas wells reduce effective fracture conductivity. Typical proppant pack laboratory experiments are oriented in such a way that phase segregation is not possible, which results in mixed flow. In this work, reservoir simulation modeling was used to determine the impact of gravity segregation. Gravity segregation is commonly ignored in design and analysis of hydraulically fractured gas wells. We found that by ignoring segregation, effective fracture conductivity can be underestimated by up to a factor of two. Hydraulic fracture treatments can be designed more effectively if effective fracture conductivity is known more accurately.
ASP Chemical Flooding Without the Need for Soft Water
Authors: Flaaten Adam K. , Nguyen Quoc P. , Zhang Jieyuan , Mohammadi Hourshad , Pope Gary A.
Published: September 2008

Alkaline-surfactant-polymer (ASP) flooding using conventional alkali requires soft water. However, soft water is not always available, and softening hard brines may be very costly or infeasible in many cases depending on the location, the brine composition and other factors. For instance, conventional ASP uses sodium carbonate to reduce the adsorption of the surfactant and generate soap in-situ by reacting with acidic crude oils; however, calcium carbonate precipitates unless the brine is soft. A form of borax known as metaborate has been found to sequester divalent cations such as Ca++ and prevent precipitation. This approach has been combined with the screening and selection of surfactant formulations that will perform well with brines with high salinity and hardness. We demonstrate this approach in this paper by combining high performance, low cost surfactants with co-surfactants that increase salinity and hardness tolerance with metaborate. Chemical formulations containing surfactants and alkali in hard brine were screened for performance and tolerance using microemulsion phase behavior experiments and crude at reservoir temperature. A formulation was found that with an optimum salinity of 120,000 ppm TDS (with 6600 ppm divalent cations) that performed well in core floods with high oil recovery and almost zero final chemical flood residual oil saturation. Additionally, chemical formulations containing sodium metaborate and hard brine gave nearly 100% oil recovery, with no indication of precipitate formation. Metaborate chemistry was incorporated into the mechanistic UTCHEM simulator and the simulator was then used to model the core floods. Overall, novel ASP with metaborate performed comparable to conventional ASP using sodium carbonate in soft water, demonstrating advancements in ASP adaptation to hard, saline reservoirs without the need for soft brine, which increases the number of oil reservoirs that are candidates for enhanced oil recovery using ASP flooding.
Responsive Cementing Material Prevents Annular Leaks in Gas Wells
Authors: Bouras H. , Doumaz N. , Bellabarba M. , Caceres E. , Mananga S. , Le Roy-Delage S. , Abd-El Aziz M. Gamal , Benberber M. Rebbou
Published: September 2008

In a traditionally cemented well, the integrity of the cement sheath surrounding the casing, and the bond between the cement and the formation or casing are essential components of hydraulic isolation. A well-cemented casing is designed to maintain hydraulic isolation throughout the productive life of the well and after abandonment. With advances in cementing technology, slurries have been designed that result in cement sheaths that can resist planned wellbore stresses without failure. Once the cement has set, however, the fixed set-cement properties do not address stresses that have not been planned for, and that may ultimately result in cement sheath failure.

This study considers the case of well construction as part of a new gas field exploration in Algeria. Wells drilled in this area have been prone to developing annular gas leaks in the weeks and months following cementing operations. To prevent the loss of isolation and reestablish hydraulic integrity in the event of cement failure, a new cement-based sealant was incorporated into the well construction plan. This reactive material responds to hydrocarbon leaks that occur because of fissures in the cement, debonding of cement from the formation or the development of a microannulus between the cement and the casing. These leaks trigger a self-healing response, sealing the leak path, and restoring well integrity. Using this sealant material has reduced the incidence and likelihood of leaking wells in an area where such problems are common, and eliminated the potential time and cost associated with leak remediation.
Bridging the Gap Between Real-Time Optimization and Information-Based Technologies
Authors: Brulé Michael , Charalambous Yanni , Crawford Mark L. , Crawley Charles
Published: September 2008

For the past several years, the problem of reducing time-to-decision in field operations and capital projects has been repeatedly described and analyzed in qualitative and anecdotal terms. In this paper, we take an engineering approach to measure and understand the problem in quantitative and fact-based terms. We first review the mission of the SPE IT Technical Section–Oilfield Integration (SPE ITTS OI) subcommittee. Several contexts of oilfield integration and their role in Digital Oilfield of the Future (DOFF) initiatives are identified. We discuss the results of our study, and compare the results with those from other studies conducted by the SPE and also by two integrated oil companies (IOCs). We address the goal of "reducing time to decision," and show how even the most basic data-integration gaps can slow decisions with great economic impact. In information management and decision-making, the mondegreen "data commute" is the biggest problem area. The data commute absorbs over half the time that engineering and operations personnel could be spending making crucial decisions to effectively manage E&P assets. We review some case studies and their economic impact. Beyond "saving half of an engineer's time," several other more subtle gaps in the industry's current modeling and integration approaches are identified and evaluated. We conclude with showing how some of these gaps have been filled in other industries outside of oil & gas, and cite some examples that could be applicable in production surveillance and optimization.
Effect of Chloride Concentration on the Stress Corrosion Cracking (SCC) of CRA Tubulars and Methods to Enhance SCC Resistance in High-Temperature Environments
Authors: Javora Paul H. , Ke Mingjie , Schultz Katrina
Published: September 2008

Recent failures of corrosion resistant alloy (CRA) production tubing and sand control screens due to stress corrosion cracking have been reported. Investigation of these field failures revealed that calcium chloride completion brine or brine containing calcium chloride was a major component in most failures. Consequently, a growing perception is developing that calcium chloride or even calcium chloride/calcium bromide completion brine should not be considered for use in wells completed with high strength CRA tubulars in high-temperature, high-pressure environments. The impact that completion brine, temperature and acid gas have on the SCC of CRA materials in oilfield environments have been presented in several SPE and NACE publications. However, it becomes necessary to further understand the SCC behavior of high strength CRA materials in brines containing calcium chloride and/or calcium bromide, the most widely used, economical completion brines and packer fluids. The question remains: is there a chloride concentration below which high-strength CRA materials can be safely used in high-temperature well completions.

Results for CRA materials tested in calcium chloride, calcium chloride/calcium bromide, and calcium bromide brine for SCC resistance are presented, and the relationship between chloride concentration, type of CRA material, and temperature is discussed. Methods to enhance SCC resistance and minimize the sensitivity of CRA materials to its environment are presented. Practical guidelines for the use of completion brine with CRA metallurgy and chemical treatment is discussed. Results obtained from this study are provided to better design safe, economical completion brine and packer fluids for wells completed with high strength CRA tubulars.
A New Method of Plunger Lift Dynamic Analysis and Optimal Design for Gas Well Deliquification
Authors: Tang Yula , Liang Zheng
Published: September 2008

This work presents a new dynamic model to describe the plunger motion by considering the changes of the tubing and casing pressures, liquid accumulation, liquid fallback, and the resistance force to the plunger. The characteristics of the tubing and casing pressures in plunger-lifted gas well are described quantitatively according to a field test data set. A better liquid accumulation mechanism is proposed. The effect of liquid falling back and liquid transfer from the tubing into the annulus during shutting-in period is specially considered for liquid accumulation and slug height modeling. The new method improves the prediction precision compared to the conventional methods that assume the constant tubing pressure for the entire process. The resistance coefficients of the plunge motion in four different phases are determined by combining the dynamic model with field test data. An example is given to illustrate the dynamic performance of plunger lift and the optimal design. The principle and approach to optimize plunger lift for dewatering gas well are proposed and discussed.
Multi-Row Steel PDC Drill Bit Technology Redefines Performance Standards in Hard, Interbedded, and Abrasive Applications
Authors: Beaton Tim , Krooshoop Mike , Herman J. J.
Published: September 2008

One of the biggest ongoing challenges to the successful production of many hard, interbedded and abrasive applications is the ability to improve drilling efficiency. In many of these applications, the use of PDC drill bits has been sporadic as many formations have been labeled ‘not PDC drillable’. As a result, these intervals often include several trips to change out drill bits (both rollercone and PDC drill bits of different types) in an attempt to maximize drilling performance. While PDC drill bits have generally proven to drill with higher ROP than rollercone bits, in these difficult drilling environments, the ROP differential can be very small, and the durability differential can be very large.

A new line of steel bodied drill bits has recently been introduced that has shown dramatic improvements in drilling efficiency in highly difficult Western Canadian drilling applications. These new steel bodied drill bits incorporate a second row of PDC cutters to add durability to the bit while still remaining aggressive enough to drill at a high ROP. The use of steel as a body material makes it possible to have the best of both worlds – a bit with very high diamond volume for excellent durability (two rows of PDC cutters per blade) while also achieving a high void volume and large junk slot area for excellent cleaning. New techniques have also been developed to protect the steel body from the typical erosion and wear that has historically been seen in highly abrasive applications.

Recent runs with this new line of drill bits have been recorded in intervals and through formations previously only drilled with rollercone bits. The new technology developed for these bits allows higher ROP and longer runs in demanding applications. In one challenging well in British Colombia, a series of these new steel multi-row bits drilled nearly twice as fast and over 30% more footage per bit than a direct offset well – saving days off the drilling curve.
Pain and Regret
Authors: Haskett William J.
Published: September 2008

The assessment of Regret and Pain of Regret is an important decision focused step in the evaluation of significant go / no go decisions. Regret is the probability that the opportunity will fail to meet its objectives; that management will regret the decision made to enter, leave prematurely, or decline an opportunity. Pain of Regret is the magnitude of hurt or injury to the organization given the occurrence of Regret. Pain can be a loss of value, competitive advantage, resources, or even shareholder confidence. As with Risk and Uncertainty, or Dependency and Correlation, Regret and the Pain of Regret is a pairing of a probability gate and a ranged element. But more importantly, Regret and Pain strike to the very core of the decision process; they relate directly to the objectives of the opportunity whether they are economic, competitive, or strategic. As such, assessment of Pain and regret is more than a calculation.

While management often centers in on the expected NPV, and analysts have embraced the concept of probabilistic assessment, it is the avoidance of Pain and Regret that often carries the day. Pain and Regret assessment offers management a way to express, with clarity, the objectives expected for an opportunity in a broader context, as well as way to understand the threat to the organization from failure.

While Pain and Regret assessment is typically carried out in the context of project entry, the decision to walk from a project may also carry disappointment, especially when a competitor takes over and is successful. Unconventional Resource Plays can be a decision confidence minefield. How much do you invest in your pilot phase? How sure are you of a viable project? How big a threat of loss will you take before you elect to walk from a project? How confident do you have to (want to) be in your go forward decision? How likely are you to be making the wrong decision?

While it will never be possible to completely eliminate errors of commission or omission, understanding the potential Pain and Regret of a decision provides benefits well beyond possible value metric improvement, or identification of mitigation opportunities. Understanding Pain and Regret provides a more complete understanding of decisions and leads directly to confidence through clarity.
Thru-Tubing Conveyed ESP Pump Replacement--Live Well Intervention
Authors: Dinkins Walter , Tetzlaff Steve , Patterson John C. , Hunt Hai , Nezaticky Peter , Rodgers James , Chambers Bret
Published: September 2008

ConocoPhillips Alaska, Inc. (CPAI) began installing Electric Submersible Pumps (ESP) on the North Slope in 1996. ConocoPhillips soon found that a frequent mode of ESP failure was pump wear caused by abrasives (sand/silt) or pump plugging (sand/scale). The high cost and long lead times associated with North Slope rig workovers drove the need to find an economical way to pull and replace worn or plugged pumps.

Thru-Tubing Conveyed (TTC) electric submersible pump technology was developed by Centrilift and ConocoPhillips to address this issue. TTC technology allows electric submersible pumps to be changed out on live wells without the need to kill the well and work it over. When a TTC pump replacement is performed, the pump is pulled and replaced with slickline or coiled tubing while the tubing, seal section, motor, power cable, and down hole gauges remain in place. The pump can be replaced as many times as necessary until a failure occurs in the tubing, seal section, motor, or power cable.

Centrilift and ConocoPhillips initially started with Thru-Tubing Conveyed Electric Submersible Progressive Cavity Pumps (TTCESPCP), which are capable of handling high solids production at lower rates. As well productivity increased with the shifting focus from vertical to horizontal/multilateral wells, TTC technology was adapted to centrifugal pumps to handle increased flow rates. The Thru-Tubing Conveyed Electric Submersible (centrifugal) pumps (TTCESP) are capable of handling high fluid and gas rates and moderately high solids production.

CPAI and Centrilift have run TTCESPCPs for 10 years and TTCESPs for seven years. This paper discusses the positive and negative results CPAI and Centrilift have experienced with TTCESPCP (progressive cavity) and TTCESP (centrifugal) systems. Lessons learned, ESP run life statistics, and economic analyses are included.
Enterovirus is Not Present in Placentas from Cases of Perinatal Depression Using Polymerase Chain Reaction Analysis
Authors: Cover Jesse , Popek Edwina , Wyckoff Myra , Leos N. Kristine , Rogers Beverly Barton
Published: September 2008

Enteroviruses have been implicated as a cause of low Apgar scores in conjunction with perinatal seizures and respiratory insufficiency. Using in-situ reverse transcriptase polymerase chain reaction (in-situ PCR), Nuovo et al detected enterovirus in up to 86% of placentas from perinates exhibiting these symptoms. In-situ PCR has been the only method employed to assess for the presence of enterovirus in this specific patient population. The purpose of our study was to use PCR amplification of enterovirus from extracted RNA to confirm these observations. RNA was extracted from 26 placentas of infants with low Apgar scores, perinatal seizures, and respiratory insufficiency. Each extraction was positive for beta-actin RNA, which confirmed that the integrity of RNA was maintained in the sample. Enterovirus RNA was not detected in any of the cases. Our results indicate that enterovirus is not present in placentas from neonates with the combination of low Apgar scores, respiratory insufficiency, and seizures, as previously reported.
ON SOLUTIONS OF ONE 6‐TH ORDER NONLINEAR BOUNDARY VALUE PROBLEM
Authors: Garbuza Tatjana
Published: September 2008

A special technique based on the analysis of oscillatory behaviour of linear equations is applied to investigation of a nonlinear boundary value problem of sixth order. We get the estimation of the number of solutions to boundary value problems of the type x(6) = f(t, x), x(a) = A, x′ (a) = A 1, x″(a) = A 2, x′″(a) = A 3, x(b) = B, x′(b) = B1 , where f is continuous together with the partial derivative f′x which is supposed to be positive. We assume also that at least one solution of the problem under consideration exists.
THRESHOLD AND STABILITY RESULTS FOR A MALARIA MODEL IN A POPULATION WITH PROTECTIVE INTERVENTION AMONG HIGH‐RISK GROUPS
Authors: Tumwiine Julius , Mugisha Joseph Y.T. , Luboobi Livingstone S.
Published: September 2008

We develop a mathematical model for the dynamics of malaria with a varying population for which new individuals are recruited through immigration and births. In the model, we assume that non‐immune travellers move to endemic regions with sprays, smear themselves with jelly that is repellent to mosquitoes on arrival in malarious regions, others take long term antimalarials, and pregnant women and infants receive full treatment doses at intervals even when they are not sick from malaria (commonly referred to as intermittent preventive therapy). We introduce more features that describe the dynamics of the disease for the control strategies that protect the above vulnerable groups. The model analysis is done and equilibrium points are analyzed to establish their local and global stability. The threshold of the disease, the control reproduction number, is established for which the disease can be eliminated.
Gender and Clinical Status in Burnout in Medicine
Authors: Sarma Deesha , Chiu David T. , Kimball Alexa B.
Published: April 2024

This survey study assesses feelings of satisfaction, stress, and burnout by gender and clinical status among health care workers at a single academic center.
Constructing Bipolar Dual‐Active Sites through High‐Entropy‐Induced Electric Dipole Transition for Decoupling Oxygen Redox
Authors: Zhang Qi , Zheng Zhiyang , Gao Runhua , Xiao Xiao , Jiao Miaolun , Wang Boran , Zhou Guangmin , Cheng Hui‐Ming
Published: April 2024

It remains a significant challenge to construct active sites to break the trade‐off between oxidation and reduction processes occurring in battery cathodes with conversion mechanism, especially for the oxygen reduction and evolution reactions (ORR/OER) involved in the zinc‐air batteries (ZABs). Here, using a high‐entropy‐driven electric dipole transition strategy to activate and stabilize the tetrahedral sites is proposed, while enhancing the activity of octahedral sites through orbital hybridization in a FeCoNiMnCrO spinel oxide, thus constructing bipolar dual‐active sites with high‐low valence states, which can effectively decouple ORR/OER. The FeCoNiMnCrO high‐entropy spinel oxide with severe lattice distortion, exhibits a strong 1s→4s electric dipole transition and intense t2g(Co)/eg(Ni)‐2p(OL) orbital hybridization that regulates the electronic descriptors, eg and t2g, which leads to the formation of low‐valence Co tetrahedral sites (Coth) and high‐valence Ni octahedral sites (Nioh), resulting in a higher half‐wave potential of 0.87 V on Coth sites and a lower overpotential of 0.26 V at 10 mA cm−2 on Nioh sites as well as a superior performance of ZABs compared to low/mild entropy spinel oxides. Therefore, entropy engineering presents a distinctive approach for designing catalytic sites by inducing novel electromagnetic properties in materials across various electrocatalytic reactions, particularly for decoupling systems.
Rational Design and Precise Synthesis of Single‐Atom Alloy Catalysts for the Selective Hydrogenation of Nitroarenes
Authors: Feng Haisong , Liu Wei , Wang Lei , Xu Enze , Pang Donghui , Ren Zhen , Wang Si , Zhao Shiquan , Deng Yuan , Liu Tianyong , Yang Yusen , Zhang Xin , Li Feng , Wei Min
Published: April 2024

Single‐atom alloys (SAAs) have gained increasing prominence in the field of selective hydrogenation reactions due to their uniform distribution of active sites and the unique host‐guest metal interactions. Herein, 15 SAAs are constructed to comprehensively elucidate the relationship between host‐guest metal interaction and catalytic performance in the selective hydrogenation of 4‐nitrostyrene (4‐NS) by density functional theory (DFT) calculations. The results demonstrate that the SAAs with strong host‐guest metal interactions exhibit a preference for N─O bond cleavage, and the reaction energy barrier of the hydrogenation process is primarily influenced by the host metal. Among them, Ir1Ni SAA stands out as the prime catalyst candidate, showcasing exceptional activity and selectivity. Furthermore, the Ir1Ni SAA is subsequently prepared through precise synthesis techniques and evaluated in the selective hydrogenation of 4‐NS to 4‐aminostyrene (4‐AS). As anticipated, the Ir1Ni SAA demonstrates extraordinary catalytic performance (yield > 96%). In situ FT‐IR experiments and DFT calculations further confirmed that the unique host‐guest metal interaction at the Ir‐Ni interface site of Ir1Ni SAA endows it with excellent 4‐NS selective hydrogenation ability. This work provides valuable insights into enhancing the performance of SAAs catalysts in selective hydrogenation reactions by modulating the host‐guest metal interactions.
Engineering of Zinc Finger Nucleases Through Structural Modeling Improves Genome Editing Efficiency in Cells
Authors: Katayama Shota , Watanabe Masahiro , Kato Yoshio , Nomura Wataru , Yamamoto Takashi
Published: April 2024

Genome Editing is widely used in biomedical research and medicine. Zinc finger nucleases (ZFNs) are smaller in size than transcription activator‐like effector (TALE) nucleases (TALENs) and CRISPR‐Cas9. Therefore, ZFN‐encoding DNAs can be easily packaged into a viral vector with limited cargo space, such as adeno‐associated virus (AAV) vectors, for in vivo and clinical applications. ZFNs have great potential for translational research and clinical use. However, constructing functional ZFNs and improving their genome editing efficiency is extremely difficult. Here, the efficient construction of functional ZFNs and the improvement of their genome editing efficiency using AlphaFold, Coot, and Rosetta are described. Plasmids encoding ZFNs consisting of six fingers using publicly available zinc‐finger resources are assembled. Two functional ZFNs from the ten ZFNs tested are successfully obtained. Furthermore, the engineering of ZFNs using AlphaFold, Coot, or Rosetta increases the efficiency of genome editing by 5%, demonstrating the effectiveness of engineering ZFNs based on structural modeling.
Advanced Cellulosic Materials Toward High‐Performance Metal Ion Batteries
Authors: Wei Jing , Ma Qianyi , Teng Youchao , Yang Tingzhou , Wong Ka Ho , Cui Yunqi , Zheng Bowu , Li Dagang , Luo Dan , Yu Aiping
Published: April 2024

Nanocellulose and its derivatives represent the most abundant biopolymers on Earth, offering a wide range of advantages, including versatility in preparation, customizable functional group incorporation, and compatibility with various materials. They open up new horizons in the development of various types of metal‐ion batteries (MIBs). This work concisely categorizes nanocellulose design strategies, including rational isolation, surface chemical enhancement, and effective physical treatments. Subsequently, an overview of recent advancements in utilizing nanocellulose and its derivatives to enhance the performance of MIBs, from lithium‐ion batteries (LIBs) to post lithium‐ion batteries (e.g., Na+, K+, Zn2+, Mg2+, Ca2+) are provided. The pivotal roles of nanocellulose in electrode design, interface engineering, electrolyte modification, and binder optimization are highlighted. Lastly, the challenges and prospects of utilizing nanocellulose and its derivatives in MIBs are delved into. This work aims to comprehensively cover recent developments in nanocellulose surface modification strategies and illuminate their current applications in emerging MIBs with impressive energy and power densities.
Early synapsids neurosensory diversity revealed by CT and synchrotron scanning
Authors: Benoit J. , Araujo R. , Lund E. S. , Bolton A. , Lafferty T. , Macungo Z. , Fernandez V.
Published: April 2024

Non‐mammaliaform synapsids (NMS) represent the closest relatives of today's mammals among the early amniotes. Exploring their brain and nervous system is key to understanding how mammals evolved. Here, using CT and Synchrotron scanning, we document for the first time three extreme cases of neurosensory and behavioral adaptations that probe into the wide range of unexpected NMS paleoneurological diversity. First, we describe adaptations to low‐frequency hearing and low‐light conditions in the non‐mammalian cynodont Cistecynodon parvus, supporting adaptations to an obligatory fossorial lifestyle. Second, we describe the uniquely complex and three‐dimensional maxillary canal morphology of the biarmosuchian Pachydectes elsi, which suggests that it may have used its cranial bosses for display or low‐energy combat. Finally, we introduce a paleopathology found in the skull of Moschognathus whaitsi. Since the specimen was not fully grown, this condition suggests the possibility that this species might have engaged in playful fighting as juveniles—a behavior that is both social and structured. Additionally, this paper discusses other evidence that could indicate that tapinocephalid dinocephalians were social animals, living and interacting closely with one another. Altogether, these examples evidence the wide range of diversity of neurological structures and complex behavior in NMS.
Event‐triggered H∞ control for fractional‐order time‐delay systems
Authors: Cong Huong Dinh
Published: April 2024

This paper considers the problem of designing event‐triggered
state feedback controllers for uncertain fractional‐order systems subject to time‐varying delays. An event‐triggered
controller is proposed based on an event‐triggered mechanism and the refined fractional‐order Razumikhin theorem. This controller guarantees the uniformly asymptotic stability of the controlled system while maintaining a predefined
performance index. The uniformly asymptotic stability of the controlled system is understood that the zero solution of the uncertain fractional‐order time‐delay systems without external disturbance is uniformly asymptotically stable. The main difficulty of this problem lies in the memory and heritability characteristics of the fractional‐order calculus operator, particularly in the context of delayed fractional‐order systems, where preventing the occurrence of the Zeno phenomenon is paramount. The Zeno phenomenon exists when an infinite number of discrete transitions occur in a finite time interval. To overcome this difficulty, new event‐triggered
state feedback controllers without Zeno behaviors are designed based on inequality techniques and several essential properties of fractional‐order calculus. Finally, the effectiveness and feasibility of the proposed method are demonstrated by a numerical example.
Fixed‐time observer‐based heading control of a paraglider recovery system with input saturation
Authors: Guo Yiming , Yan Jianguo , Xing Xiaojun , Xiao Bing
Published: April 2024

This paper investigates a challenging heading control problem for a flexible paraglider recovery system with input saturation. A fixed‐time observer‐based control approach is presented. In this approach, a fixed‐time disturbance observer is preliminarily designed to estimate the aerodynamic uncertainties and the complex coupling of the subsystems. A fixed‐time auxiliary system is then proposed to compensate for input saturation impact. With the application of the estimated and compensation values, a novel heading tracking controller is synthesized with compensated disturbance. The key feature of the scheme is that it is not only fixed time stable regardless of any initial state, but also it prevents control performance degradation due to input saturation and various disturbances. Simulation results verify the effectiveness of the proposed method.
Highly sensitive liquid chromatography–mass spectrometry method for the quantitative analysis of mometasone furoate in human plasma: Method validation and application to clinical pharmacokinetic studies
Authors: Heudi Olivier , Jain Monish , Winter Serge
Published: April 2024

We report the development and the validation of a sensitive liquid chromatography–mass spectrometry (LC‐MS/MS) method for mometasone furoate (MF) analysis in human plasma. Plasma samples were processed through liquid–liquid extraction and analyzed using LC‐MS/MS operating in positive mode using multiple reaction monitoring of transitions m/z 520.9 → 355.0 and m/z 525.8 → 355.0 for MF and the internal standard (IS), respectively. Separation was achieved at 1.0 mL/min on a C18 column using a gradient elution of mobile phase of 0.05% ammonia in water (phase A) and acetonitrile (phase B). The assay range was 0.250–100 pg/mL and proved to be accurate and precise MF. Normalized recoveries were consistent and reproducible with a coefficient of variation (CV%) value of 6.0. The CV (%) of the IS normalized matrix factor was not observed in normal, lipemic, and hemolyzed plasmas. Dilutions of 1:10 were accurately quantified. A cycle of three freeze and thaw and stabilities at room temperature and on the autosampler were demonstrated. In addition, MF in the presence of indacaterol and glycopyrronium was proven to be stable at −70°C for at least 157 days. The present method was successfully applied to quantify MF in patients receiving MF, indacaterol, and glycopyrronium as a fixed‐dose combination.
Method development and validation for the estimation of gedatolisib in mouse plasma by tandem mass spectrometry and its application to pharmacokinetics studies
Authors: A B Vinod , Das Arunava
Published: April 2024

A simple and a sensitive liquid chromatography–tandem mass spectrometry method was developed and validated for the quantification of gedatolisib in mouse plasma. The extraction technique involved a simple precipitation method to extract gedatolisib and idelalisib (internal standard) from mouse plasma. A clean chromatographic separation of gedatolisib and the internal standard was achieved on an Atlantis dC18 column using an isocratic mobile phase (10 mm ammonium formate and acetonitrile; 30:70% v/v, both supplemented with 0.1% formic acid) delivered at a flow rate of 0.7 ml/min. The total run time was 2.0 min, and gedatolisib and idelalisib were eluted at 0.80 and 0.95 min, respectively. Gedatolisib was monitored at m/z 616.40 → 488.20 and idelalisib at 416.05 → 176.10. All the required parameters for the method validation were performed as per US Food and Drug Administration guidelines, and the results were within the acceptance criteria. The method was accurate and proved to be precise at a linearity range of 1.33–2667 ng/ml. The accuracy for gedatolisib in mouse plasma was in the ranges 0.99–1.06% (intra‐day) and 0.96–1.04% (inter‐day). Gedatolisib appeared to be stable in a series of stability conditions. Gedatolisib showed a good intravenous profile when administered through a solution formulation.
A rare presentation of primary cardiac myxofibrosarcoma: Case report and literature review
Authors: Soltani Sepideh , Garousi Maryam , Mirzaee Elahe , Koolaji Sogol , Nazari Hengameh , Emami Sepideh , Zare Mehrjardi Ali , Arefpour Amir Mohammad
Published: April 2024

Background

Primary cardiac myxofibrosarcoma is a rare and aggressive malignancy, with the majority of approaching strategies relying on case reports. This article provides insights into its diagnosis and treatment.

Case Presentation

This paper presents the case of a 40‐year‐old man with sudden onset hemoptysis, leading to the diagnosis of primary cardiac myxofibrosarcoma. Treatment involved open‐heart surgery to excise the left atrium tumor, followed by 6 cycles of adjuvant chemotherapy. Unfortunately, brain metastasis developed, leading to the patient's death 1 year after initial diagnosis.

Conclusion

Primary cardiac myxofibrosarcoma remains a clinical challenge with an unfavorable prognosis. Early diagnosis through advanced imaging is crucial, and research is needed to explore innovative treatments. This case underscores the complexities of managing this rare cardiac malignancy and highlights the necessity for ongoing investigations to enhance patient outcomes.
Informed Consent for Psychotherapy: The Moderating Role of Therapeutic Alliance, Prior Knowledge and Autonomous Motivation on Decision‐Making and Treatment Expectation
Authors: Ladwig Sönke , Pauls Franz , Gerke Leonie , Nestoriuc Yvonne
Published: April 2024

Background

Informed consent is an ethical prerequisite for psychotherapy. There are no routinely used standardized strategies for obtaining informed consent. A new optimized informed consent consultation (OIC) strengthened treatment‐relevant aspects. It remains unclear which factors influence the OIC efficacy regarding clinical and decision‐related outcomes.

Methods

N = 122 adults were included in a randomized controlled online trial. Participants received an information brochure on psychotherapy (TAU; n = 61) or OIC + TAU (n = 61). The main and interaction effects of group allocation, therapeutic alliance, prior knowledge about psychotherapy and treatment motivation on treatment expectations, decisional conflict and capacity to consent were tested. Floodlight analyses were conducted for significant interactions.

Results

Large interaction effects were shown between treatment motivation and group allocation on treatment expectations (β = −0.53) and between prior knowledge and group assignment on capacity to consent (β = 0.68). The interaction between treatment motivation and group allocation was significant up to a motivation score of 5.54 (range: 1–7). The interaction between prior knowledge and group assignment was significant up to a knowledge score of 14.38 (range: 5–20).

Conclusion

Moderator analyses indicated varying efficacy degrees for the OIC regarding decisional outcomes and expectation. Especially patients with little treatment motivation or low prior knowledge benefited from optimized information about the efficacy and possible side effects of psychotherapy.

Trial Registration: PsychArchives (https://doi.org/10.23668/psycharchives.4929): 17.06.2021
Use of current automatic smoke evacuation system in flexible gastrointestinal endoscopy: Its feasibility and potential usefulness
Authors: Nose Yohei , Kato Motohiko , Aoyagi Shoma , Akeo Kazunori , Yamashita Kotaro , Saito Takuro , Tanaka Koji , Yamamoto Kazuyoshi , Makino Tomoki , Takahashi Tsuyoshi , Kurokawa Yukinori , Eguchi Hidetoshi , Doki Yuichiro , Nakajima Kiyokazu
Published: April 2024

Objectives

Flexible endoscopy does not have a system that can automatically evacuate surgical smoke generated in the gastrointestinal lumen. We aimed to investigate the feasibility and potential usefulness of automatic smoke evacuation systems in flexible endoscopy.

Methods

[Bench] After surgical smoke generated in the stomach was evacuated by the evacuator, the degree of residual smoke and gastric luminal collapse were evaluated to optimize the evacuator settings. [Animal] Insufflation, suction, and total operation time to complete the protocol of 10 cauterizations of the gastric mucosa were measured in three groups: “manual suction only,” “manual suction with automatic evacuation (50% force),” and “manual suction with automatic evacuation (70% force).” The stability of endoscopic visualization and operability was evaluated by 10 endoscopists blinded to those suction settings, and the number of manual suctions, insufflations, and total operation time were measured.

Results

[Bench] The degree of residual smoke and gastric luminal collapse were inversely correlated. [Animal] When the automatic evacuator was partially used, there was no difference in the insufflation time, but the suction time (vs 50%; p = 0.011, vs. 70%; p = 0.011) and total operation time (vs. 50%; p = 0.012, vs. 70%; p = 0.036) were significantly reduced compared to manual operation only. Furthermore, manual suction with automatic evacuation (50% force) significantly improved the stability of endoscopic visualization and operability compared to manual operation only (p = 0.041, p = 0.0085).

Conclusions

The automatic smoke evacuation in flexible gastrointestinal endoscopy was potentially feasible and useful by improving the device setting.
Quantitative determination of R/S‐methadone in human serum using ultra‐high performance supercritical fluid chromatography‐tandem mass spectrometry: A method for routine use
Authors: Hansen Miriam , Havnen Hilde , Andreassen Trine Naalsund , Spigset Olav , Hegstad Solfrid
Published: April 2024

Methadone has two enantiomers, which exhibit differences in pharmacological effects, with R‐methadone being the active and S‐methadone the inactive enantiomer. A robust, simple and rapid method for chiral separation of the two enantiomers in serum samples using ultra‐high performance supercritical fluid chromatography‐tandem mass spectrometry (UHPSFC‐MSMS) has been developed and validated. Enantiomeric separation was achieved using a Chiralpak IH‐3 column with a mobile phase consisting of CO2 and 30mM ammonium acetate in methanol/water (98/2, v/v). Runtime was 4 minutes. Sample preparation was semi‐automated using a Hamilton ML Star robot with protein precipitation, and phospholipid removal was carried out using a Waters OSTRO™ 96‐well plate. The calibration range was 50.0–1,500 nM for each enantiomer. The between‐assay relative standard deviations were in the range of 1.2–3.6%. Matrix effects ranged from 99% to 115% corrected with internal standard. The method has been implemented in our laboratory and has proven to be a robust and reliable method for determining the ratio of R/S‐methadone in authentic patient samples.
Game changers in international higher education
Authors: Dennis Marguerite J.
Published: April 2024

In March 2024's column I shared some of the game changers in U.S. higher education. This month's article will feature some of the game changers taking place worldwide. The purpose of both articles is to bring awareness to policies and initiatives that may impact your administrative work now, and potentially, in the future.
Practical strategies for establishing yourself as a responsible leader
Authors: Cain Butler
Published: April 2024

Establishing a reputation as a responsible leader within higher education takes time, effort, and consideration. Fortunately, department chairs and other program managers can follow a variety of practical strategies to improve their standing as reliable leaders. Such strategies create growth opportunities for academic programs, help build trusting relationships, and effectively position people for professional advancement. This article groups strategies into four categories: building a reputation for financial management, building a leadership reputation among faculty and staff, building a leadership reputation among administrators, and supporting future academic leaders.