Excellent Feasibility Research Articles

Abstract 11483: Rationale and Design of Randomized Controlled Trial Evaluating an Atrial Appendage Micrograft Transplantation in Conjunction With Coronary Artery Bypass Surgery

Introduction: In addition to the revascularization therapies for ischemic heart disease (IHD), such as coronary artery bypass grafting (CABG), tissue-engineered cell therapies can help further improve myocardial repair. First clinical results on autologous right atrial appendage-derived micrograft (AAM) transplantation have demonstrated excellent safety and feasibility profiles and suggested a therapeutic effect on myocardial viability. This randomized clinical trial aims to extend the evaluation of efficacy of AAMs transplantation when combined with CABG surgery. Methods and objectives: This double-blinded randomized controlled AAMS2 trial will assess the benefits, safety, and feasibility of the perioperatively assembled and epicardially transplanted AAMs-patch in conjunction with CABG. The trial recruits a total of 50 patients, half of which are randomized to receive the AAMs-patch (CABG+AAMs) and the other half to undergo a standard CABG. Prior to surgery, cardiac structure and function are assessed with late gadolinium enhancement cardiac magnetic resonance imaging (LGE-CMRI), electrocardiogram, and transthoracic echocardiography (TTE). LGE-CMRI, electrocardiogram, and TTE are repeated at 6-month follow-up for structural and functional comparisons to baseline. The primary endpoints focus on the efficacy of the AAMs patch as evaluated by LGE-CMRI and TTE as well as changes in health-related quality of life assessments, 6-minute walk test or N-terminal-pro-BNP levels. The secondary endpoints centre on feasibility and safety. For molecular and especially RNA-level analysis of the response to therapy in blood, RNA-stabilized whole blood and plasma samples are collected. Conclusions: The AAMS2 trial is expected to provide further feasibility and safety data as well as insights for efficacy of epicardial AAMs-patch transplantation when administered during CABG surgery.

A Bioinspired Orthopedic Biomaterial with Tunable Mechanical Properties Based on Sintered Titanium Fibers.

Inadequate mechanical compliance of orthopedic implants can result in excessive strain of the bone interface, and ultimately, aseptic loosening. It is hypothesized that a fiber-based biometal with adjustable anisotropic mechanical properties can reduce interface strain, facilitatecontinuous remodeling, and improve implant survival under complex loads. The biometal is based on strategically layered sintered titanium fibers. Six different topologies are manufactured. Specimens are tested under compression in three orthogonal axes under 3-point bending and torsion until failure. Biocompatibility testing involves murine osteoblasts. Osseointegration is investigated by micro-computed tomography and histomorphometry after implantation in a metaphyseal trepanation model in sheep. The material demonstrates compressive yield strengths of up to 50MPa and anisotropy correlating closely with fiber layout. Samples with 75% porosity are both stronger and stiffer than those with 85% porosity. The highest bending modulus is found in samples with parallel fiber orientation, while the highest shear modulus is found in cross-ply layouts. Cell metabolism and morphology indicate uncompromised biocompatibility. Implants demonstrate robust circumferential osseointegration in vivo after 8 weeks. The biometal introduced in this study demonstrates anisotropic mechanical properties similar to bone, and excellent osteoconductivity and feasibility as an orthopedic implant material.

Boosting sparrow search algorithm for multi-strategy-assist engineering optimization problems

An improved optimization algorithm, namely, multi-strategy-sparrow search algorithm (MSSSA), is proposed to solve highly non-linear optimization problems. In MSSSA, a circle map is utilized to improve the quality of the population. Moreover, the adaptive survival escape strategy (ASES) is proposed to enhance the survival ability of sparrows. In the producer stage, the craziness factor integrated with ASES is introduced to enhance the search accuracy and survival ability. In the scout stage, the ASES facilitates sparrows successful escape from danger. Besides, opposition-based learning or Gaussian–Chachy variation helps optimal individuals escape from local solutions. The performance of the MSSSA is investigated on the well-known 23 basic functions and CEC2014 test suite. Furthermore, the MSSSA is applied to optimize the real-life engineering optimization problems. The results show that the algorithm presents excellent feasibility and practicality compared with other state-of-the-art optimization algorithms.

A Smoking Cessation Mobile App for Persons Living With HIV: Preliminary Efficacy and Feasibility Study.

BackgroundThe prevalence of smoking in the United States general population has gradually declined to the lowest rate ever recorded; however, this has not been true for persons with HIV.ObjectiveWe conducted a pilot test to assess the feasibility and efficacy of the Lumme Quit Smoking mobile app and smartwatch combination with sensing capabilities to improve smoking cessation in persons with HIV.MethodsA total of 40 participants were enrolled in the study and randomly assigned 1:1 to the control arm, which received an 8-week supply of nicotine replacement therapy, a 30-minute smoking cessation counseling session, and weekly check-in calls with study staff, or to the intervention arm, which additionally received the Lumme Quit Smoking app and smartwatch.ResultsOf the 40 participants enrolled, 37 completed the follow-up study assessments and 16 used the app every day during the 56-day period. During the 6-month recruitment and enrollment period, 122 people were screened for eligibility, with 67.2% (82/122) deemed ineligible. Smoking criteria and incompatible tech were the major reasons for ineligibility. There was no difference in the proportion of 7-day point prevalence abstinence by study arm and no significant decrease in exhaled carbon monoxide for the intervention and control arms separately. However, the average exhaled carbon monoxide decreased over time when analyzing both arms together (P=.02).ConclusionsResults suggest excellent feasibility and acceptability of using a smoking sensor app among this smoking population. The knowledge gained from this research will enable the scientific community, clinicians, and community stakeholders to improve tobacco cessation outcomes for persons with HIV.Trial RegistrationClinicalTrials.gov NCT04808609; https://clinicaltrials.gov/ct2/show/NCT04808609

Mineralization of Dandelion as an Enzyme-like Nanoelectrode for Ultrasensitive Monitoring of H2O2 at a Single-Cell Level

Cellular heterogeneity is one of the major challenges in understanding cell-to-cell differences in therapeutics. A sensitive electrode with a micro/nanoscale diameter is urgently needed for sensing molecules at a single-cell level. A dandelion seed has a bristly fiber structure and measures roughly 14 mm. Inspired by this, a solid-state electrochemiluminescence (ECL) nanoelectrode based on a dandelion seed is developed for the ultrasensitive analysis of H2O2. A layer of gold nanoparticles is electroless-plated on the dandelion seeds to enable the bio-fibers to work as conductive electrodes. Because ECL is a surface-confined process, a layer of MIL-100(Fe) (MIL = Materials of Institut Lavoisier) film is coated on the fiber electrode as the carrier of a luminophore. Benefitting from the peroxidase-like activity of an iron(III) metal-organic framework (FeMOF), H2O2 is decomposed into •OH radicals, which in situ serve as the coreactants for the ECL emission. The design of this luminophore-in-MOF coater not only shortens the distance between the detection interface and the coreactant molecules but also effectively enriches the excited-state luminophore in a localized thin film. As a proof of concept, the nanosized filament tips are employed to sense the H2O2 released from different living cells at a single-cell level and demonstrate excellent feasibility in probing the cell heterogeneity. As a biomass electrode, the superiority of a dandelion nanoelectrode is that it is inexpensive, scalable, assessable, and environmentally friendly. This study not only advanced plant fibers as conductive nanoelectrodes but also, more importantly, offered access to the development of solid-state ECL nanoelectrodes with single-cell sensitivity.

Pd-Decorated NiCo2O4 Nanotubes Derived from Template-Free Process for Improved Electrocatalytic Glucose Oxidation

The electrode materials for highly efficient glucose oxidation reaction (GOR) are vital for nonenzymatic glucose sensors (NEGS) and direct glucose fuel cells. The Pd-decorated NiCo2O4 nanotubes (Pd/NiCo2O4 NTs) were prepared through the template-free process. Pd/NiCo2O4 NTs presented highly improved electrocatalytic activity for glucose oxidation. When applied to glucose detection, Pd/NiCo2O4 NTs displayed superior sensing performance with a wide detection range of 5 [Formula: see text]M–9 mM. The sensitivity and detection limit are 214.2 [Formula: see text] and 1.6 [Formula: see text]M, respectively. Moreover, the Pd/NiCo2O4 NTs sensors also demonstrated excellent selectivity and feasibility for glucose detection for serum sample analysis.

Digital Graphic Follow-up Tool (Rehabkompassen) for Identifying Rehabilitation Needs Among People After Stroke: Randomized Clinical Feasibility Study.

BackgroundStroke is a leading cause of disability among adults, with heavy social and economic burden worldwide. A cost-effective solution is urgently needed to facilitate the identification of individual rehabilitation needs and thereby provide tailored rehabilitations to reduce disability among people who have had a stroke. A novel digital graphic follow-up tool Rehabkompassen has recently been developed to facilitate capturing the multidimensional rehabilitation needs of people who have had a stroke.ObjectiveThe aim of this study was to evaluate the feasibility and acceptability of conducting a definitive trial to evaluate Rehabkompassen as a digital follow-up tool among people who have had a stroke in outpatient clinical settings.MethodsThis pilot study of Rehabkompassen was a parallel, open-label, 2-arm prospective, proof-of-concept randomized controlled trial (RCT) with an allocation ratio of 1:1 in a single outpatient clinic. Patients who have had a stroke within the 3 previous months, aged ≥18 years, and living in the community were included. The trial compared usual outpatient visits with Rehabkompassen (intervention group) and without Rehabkompassen (control group) at the 3-month follow-up as well as usual outpatient visit with Rehabkompassen at the 12-month follow-up. Information on the recruitment rate, delivery, and uptake of Rehabkompassen; assessment and outcome measures completion rates; the frequency of withdrawals; the loss of follow-up; and satisfaction scores were obtained. The key outcomes were evaluated in both groups.ResultsIn total, 28 patients (14 control, 14 Rehabkompassen) participated in this study, with 100 patients screened. The overall recruitment rate was 28% (28/100). Retention in the trial was 86% (24/28) at the 12-month follow-up. All participants used the tool as planned during their follow-ups, which provided a 100% (24/24) task completion rate of using Rehabkompassen and suggested excellent feasibility. Both patient- and physician-participants reported satisfaction with the instrument (19/24, 79% and 2/2, 100%, respectively). In all, 2 (N=2, 100%) physicians and 18 (N=24, 75%) patients were willing to use the tool in the future. Furthermore, modified Rankin Scale as the primary outcome and various stroke impacts as secondary outcomes were both successfully collected and compared in this study.ConclusionsThis study demonstrated the high feasibility and adherence of the study protocol as well as the high acceptability of Rehabkompassen among patients who have had a stroke and physicians in an outpatient setting in comparison to the predefined criterion. The information collected in this feasibility study combined with the amendments of the study protocol may improve the future definitive RCT. The results of this trial support the feasibility and acceptability of conducting a large definitive RCT.Trial RegistrationClinicalTrials.gov NCT04915027; https://clinicaltrials.gov/ct2/show/NCT04915027

Virtual Tai Chi program for patients with irritable bowel syndrome with constipation: Proof-of-concept feasibility trial.

Satisfaction with current treatment options for irritable bowel syndrome with constipation (IBS-C) is low, with many patients turning to complementary treatments. Tai Chi is a mind-body medicine practice with proven efficacy in other functional disorders. As a proof-of-concept, we tested the feasibility and preliminary clinical outcomes associated with a Tai Chi program designed for IBS-C. A total of 27 IBS-C patients participated in a single-arm trial of 8 sessions of Tai Chi delivered weekly over 7 weeks via live videoconferencing in group format. Clinical improvement was assessed via change in IBS Symptom Severity Score (IBS-SSS) from baseline to 4 weeks posttreatment (week 11) with secondary outcomes exploring symptom ratings, IBS-related quality of life (IBS-QOL), GI-specific anxiety, abdominal distention, and psychological factors. Despite substantial dropout (n=7; 26%), the treatment protocol had moderate to excellent feasibility for other criteria. Treatment satisfaction was excellent. Exit interviews confirmed high satisfaction with the program among completers, but a high burden of data collection was noted. One participant experienced an adverse event (mild, exacerbation of sciatica). There was a significant improvement in intra-individual IBS-SSS between baseline and posttreatment (average change -66.5, 95% CI -118.6 to -14.3, p=0.01). Secondary outcomes were notable for improvements in other IBS symptom scoring measures, IBS-QOL, measured abdominal diameter, and leg strength. Our data provide preliminary evidence of the feasibility of a Tai Chi intervention for IBS-C, show promise for improving outcomes, and identify more streamlined data collection as an area for further program improvement.

Latest Performance Improvement Strategies and Techniques Used in 5G Antenna Designing Technology, a Comprehensive Study.

In the recent era, fifth-generation technology (5G) has not been fully implemented in the realm of wireless communication. To have excellent accessible bandwidth feasibility, and in order to achieve the aims of 5G standards, such as higher data rates and ultrahigh-definition video streaming, the millimeter wave (mmWave) band must be employed. Services with minimal latency and many other features are feasible only in the mmWave spectrum. To avoid numerous communication complexities such as high connection losses, short wavelength, and restricted bandwidth, as well as path-loss challenges in the mmWave range, an antenna with wide bandwidth, high gain, narrow steerable beam, high isolation, low side-lobe levels, and multiband features is required to alleviate these difficulties and meet 5G communication standards. To overcome these challenges, specific strategies and techniques should be employed in the traditional antenna designing procedure to excellently improve the performance of the antenna in terms of bandwidth, gain, and efficiency and to reduce the mutual coupling effect between the closely colocated antenna elements in MIMOs and arrays. The researchers reported on a variety of bandwidth and gain improvement approaches. To gain broader coverage, traditional antenna design techniques must be modified. In this study, the latest state-of-the-art work is reviewed, such as the role of the metamaterials (MMTs), parasitic patches, hybrid feeding, EBG structure, impact of the slots with different geometrical shapes in the radiator to achieve the goal of wide bandwidth, boosted gain, reduced side-lobes level, as well as stable radiation properties. Mutual coupling reduction techniques are also briefly reported. The role of reconfigurability is focused on in this study, and at the end, the future challenges in the field of antenna design and possible remedies to such issues are reviewed.

The development of RPA and CRISPR-Cas12a based immunoassay strip for sensitive detection of genetically modified crops

Rapid detection method with high sensitivity has been expected in transgenic field screening. In this study, an ultra-sensitive visualization detection procedure based on recombinase polymerase amplification, CRISPR/Cas12a system, and lateral flow strip technology (RPA-Cas12a-LFB) was developed for the rapid detection of genetically modified (GM) crops. P-CaMV 35 S and T-NOS screening elements, the most widely covered in GM crops, were targeted. The results showed that standard plasmids as low as 10 copies and 0.01% GM crops of Bt11 and MON863 samples can be detected, demonstrating the ultra-sensitivity of the method. The assay was applied to a series of GM crop standards, and the results were consistent with those of existing methods, exhibiting the excellent specificity and feasibility. The analysis can be completed within 40 min, realizing rapid detection. Overall, an accurate, sensitive, time-saving, and instrument-independent detection system was successfully developed, providing a new strategy with ultra-sensitive capability in detection.

Corticosteroids reduce vascular ultrasound sensitivity in fast- track pathways (FTP): results from Coventry Multi-Disciplinary FTP for cranial Giant Cell Arteritis

Objectives This study aims to assess the feasibility of the Coventry ultidisciplinary fast-track cranial giant cell arteritis (FTGCA) pathway, which was set up in 2013 in collaboration with vascular physiology and ophthalmology to enable prompt multidisciplinary assessment, including ultrasound (US). This study also looks at the impact of prior corticosteroid (CS) use on the performance of US in real life. Method Data were collected retrospectively for patients who attended the Coventry FTGCA pathway between 1 January 2014 and 31 December 2017. Patients were identified from US lists and clinical details were obtained from electronic medical records. Results In total, 620 eligible patients were included in this study. US had a sensitivity of 50%, which improved to nearly 56% in CS-naïve patients. The median duration of CS use prior to US was 2 days, and sensitivity was around 46% in this group. The specificity of US was > 96%, and CS use was avoided completely in 345 patients (56%). CSs natively impacted on the utility of US, with US more likely to be false negative. Conclusions This novel multidisciplinary pathway demonstrates excellent feasibility and minimizes the use of CSs in patients without giant cell arteritis. US was performed promptly, was cost effective- and had reassuring real-life sensitivity and specificity in this cohort, with excellent patient feedback. CS-naïve patients showed higher sensitivity for US despite the short duration of CS use.

Potential of frankincense essential oil-loaded whey protein nanoparticles embedded in frankincense resin as a wound healing film based on green technology

The implementation of naturally available curative compounds or the utilization of green biopolymers especially industrial byproducts, are recently applied to develop new topical formulations for treating or managing skin wounds. In this study, frankincense (FRK) essential oil was extracted from Bosolica papyrifera oliogum resin, and encapsulated into whey protein NPs using spray drying technique. A bionanocomposite film was then prepared by embedding FRK essential oil-loaded whey protein NPs into FRK resin using solvent casting technique. Morphological analysis by TEM showed that the prepared NPs were spherical in shape with diameter of about 151 nm and EE % of about 75.9%. The fabricated film showed good tensile strength and improved sustained release of FRK essential oil compared to the oil-loaded whey protein NPs alone. Moreover, it exhibited a significant antimicrobial behavior with very weak hemolytic activity. More importantly, when this film was applied in a full thickness animal wound model, it displayed remarkably improved healing with enhanced collagen deposition associated with decline in the gene expression of interleukin-6 (IL-6) and an increase in the gene expression of transforming growth factor-β1 (TGF- β1) due to the ability of FRK essential oil to modulate inflammation and skin tissue remodeling, suggesting the excellent feasibility of this film as a highly efficient wound dressing film.

Label-free electrochemical aptasensor for rapid detection of SARS-CoV-2 spike glycoprotein based on the composite of Cu(OH)2 nanorods arrays as a high-performance surface substrate

The development of advanced electrode materials and the combination of aptamer with them have improved dramatically the performance of aptasensors. Herein, a new architecture based on copper hydroxide nanorods (Cu(OH)2 NRs) are directly grown on the surface of screen printed carbon electrode (SPCE) using a two-step in situ, very simple and fast strategy and was used as a high-performance substrate for immobilization of aptamer strings, as well as an electrochemical probe to development a label-free electrochemical aptasensor for SARS-CoV-2 spike glycoprotein measurement. The Cu(OH)2 NRs was characterized using X-ray Diffraction (XRD) and electron microscopy (FESEM). In the presence of SARS-CoV-2 spike glycoprotein, a decrease in Cu(OH)2 NRs-associated peak current was observed that can be owing to the target-aptamer complexes formation and thus blocking the electron transfer of Cu(OH)2 NRs on the surface of electrode. This strategy exhibited wide dynamic range in of 0.1 fg mL−1 to 1.2 µg mL−1 and with a high sensitivity of 1974.43 μA mM−1 cm−2 and low detection limit of 0.03 ± 0.01 fg mL−1 of SARS-CoV-2 spike glycoprotein deprived of any cross-reactivity in the presence of possible interference species. In addition, the good reproducibility, repeatability, high stability and excellent feasibility in real samples of saliva and viral transport medium (VTM) were found from the provided aptasensor. Also, the aptasensor efficiency was evaluated by real samples of sick and healthy individuals and compared with the standard polymerase chain reaction (PCR) method and acceptable results were observed.

Multilevel RNN-Based PM10 Air Quality Prediction for Industrial Internet of Things Applications in Cleanroom Environment

Adequate air ventilation systems and maintaining environmental air quality are essential things that need to be considered to create an excellent industrial environment in a company. Operating or maintaining ecological air quality is a challenge for companies to optimize the existing work environment. Especially at the economic and business level in the company are facing the main problems. In this case, monitoring and predicting future air quality are needed to maintain air quality conditions. PM10 concentration, humidity, and temperature were used to predict annual and seasonal indoor air quality using a recurrent neural network (RNN) and long short-term memory (LSTM). In this paper, we propose the IAQP method for air quality management systems that combines indoor air quality forecasting based on real-time data. To measure indoor air quality, we predict the outcome from the IIoT sensor and LoRa sensor. The result of prediction is that the multilevel RNN model outperformed the LSTM, as the model demonstrated excellent results and feasibility.

Feasibility, effectiveness and transferability of a novel mastery-based virtual reality robotic training platform for general surgery residents.

BackgroundThe annual number of robotic surgical procedures is on the rise. Robotic surgery requires unique skills compared to other surgical approaches. Simulation allows basic robot skill acquisition and enhances patient safety. The purpose of this study was to evaluate the feasibility, effectiveness, and transferability of a mastery-based curriculum using a new virtual reality (VR) robotic simulator for surgery resident training.MethodsNineteen PGY2s and 22 PGY4s were enrolled. Residents completed a pretest and posttest consisting of five VR and three previously validated inanimate tasks. Training included practicing 33 VR tasks until a total score ≥ 90% (“mastery”) was achieved using automated metrics (time, economy of motion). Inanimate performance was evaluated by two trained, blinded raters using video review metrics (time, errors, and modified OSATS). Outcomes were defined as: curriculum feasibility (completion rate, training time, repetitions), training effectiveness (pre/post training skill improvement), and skill transferability (skill transfer to validated inanimate drills). Wilcoxon signed-rank and Mann–Whitney U tests were used; median (IQR) reported.ResultsThirty-four of 41 residents (83%) achieved mastery on all 33 VR tasks; median training time was 7 h (IQR: 5′26″–8′52″). Pretest vs. post-test performance improved (all p < 0.001) according to all VR and Inanimate metrics for both PGY2 and PGY4 residents. Significant pretest performance differences were observed between PGY2 and PGY4 residents for VR but not inanimate tasks; no PGY2 vs. PGY4 posttest performance differences were observed for both VR and inanimate tasks.ConclusionThis mastery-based VR curriculum was associated with a high completion rate and excellent feasibility. Significant performance improvements were noted for both the VR and inanimate tasks, supporting training effectiveness and skill transferability. Additional studies examining validity evidence may help further refine this curriculum.

Functionalization of CNFs surface with β-cyclodextrin and decoration of hematite nanoparticles for detection and degradation of toxic fungicide carbendazim

Fungicides are widely used across the globe in agricultural sector and their ubiquitous presence is a serious concern to ecology due to their hazardous nature. Hence, we report sensitive detection and degradation of the toxic fungicide carbendazim based on a novel dual-functional nanocomposite that consists of carbon nanofibers (CNFs), β-cyclodextrin (β-CD), and hematite (α-Fe2O3) nanoparticles. The surface functionalization of CNFs with the natural polymer β-CD and the subsequent decoration with α-Fe2O3 nanoparticles through a sonochemical method were detailed. Exceptional surface-controlled electrocatalytic activity has been achieved towards the detection of carbendazim, and we have confirmed this based on cyclic voltammetry and differential pulse voltammetry techniques. Furthermore, the excellent photocatalytic activity of the prepared nanocomposite towards carbendazim was verified by evaluating the degradation rate. Apart from very low limit of detection (LOD) of 1 nM and excellent sensitivity of 37.69 μA μM−1cm−2, outstanding anti-interference property, stability, reproducibility, and repeatability were also exhibited by the developed carbendazim sensor. Moreover, we detected carbendazim in real samples including apple, orange, tomato, and river water to evince excellent practical feasibility of the developed sensor.

Interrater reliability of quantitative ultrasound measures of muscle in critically ill patients.

Quantitative neuromuscular ultrasound is increasingly used to study muscle pathology and changes in muscle mass during critical illness. Advantages of ultrasound are high axial resolution, low procedural risks, no ionizing radiation, and ease of use early in the course of disease. However, ultrasound is known to be an operator dependent imaging modality and the intensive care unit setting poses additional challenges to obtaining reliable measurements. There is limited evidence validating the feasibility and reliability of its application in this setting. To conduct a standardized protocol for measuring muscle linear depth and cross-sectional area in critically ill populations with a high degree of interrater agreement and feasibility. Prospective observational cohort study of interrater reliability. Medical intensive care unit at an academic medical center and a level one trauma and burn center. Fifteen critically ill patients were evaluated using a standardized ultrasound protocol measuring total elbow flexor, knee extensor, and tibialis anterior depth, as well as rectus femoris cross-sectional area. Each site was independently scanned by two investigators. Reliability of measurements between observers was determined by calculating intraclass correlation coefficients (ICCs) using a two-way random effects model and absolute agreement. An ICC > 0.75 was considered good and >0.90 was considered excellent. In critically ill patients, interrater reliability of linear depth measured at elbow flexor, knee extensor, tibialis anterior, and cross-sectional area of rectus femoris sites was good to excellent with ICC between 0.87 (0.54-0.97) and 0.99 (0.97-1.00). Interrater reliability was improved by creating a summary index of measures resulting in an ICC of 0.99 (0.98-1.00). Feasibility, as definite by the percentage of each measure that was obtainable, ranged from 75%-100%. Using a standardized protocol, ultrasound measures obtained in critically ill patients demonstrated high levels of interrater agreement with good to excellent feasibility.

The continuous pack-off technology: A novel water-control method and application to offshore horizontal wells of limestone reservoir

Water-control for horizontal wells is a worldwide problem, while it is even harder for limestone reservoir because of the developed fractures and caves.The formation water can be connected to the wellbore by fractures or caves directly or indirectly. Make the wells easily water flooded.Segmented water-control is the consensus of the current mainstream mechanical water-control technologies for horizontal wells, the segments confine the water break-through influence scope to the segment where the water break-through formed. In order to achieve that, all the potential water break-through fractures and caves connected to wellbore should be concentratedly divided into less segments, but that depends on the distribution of fractures and caves. Otherwise, the number and the sealing location of the packers are also relying on the engineering technology and the well status.Fracture/cave axial channeling inside the formation is another problem. The fractures and caves interwoven inside the formation. The formation water can easily flow around the packers by fractures/caves and cause the sealing failure of packers and invalid segment.Meanwhile the conventional mechanical water-control methods have no ability to limit the flow conductivity of fractures and caves. In the segments with fractures/caves developed, the producing degree of the matrix will be low.As a result, the application effect of conventional water-control methods in limestone reservoir horizontal wells is limited.To conquer the fracture/cave channeling and achieve the water-control effect at the meantime, the article proposed a novel mechanical water-control method which combined particle-filling with inflow control device screens. The particle-filling is not an absolute sealing, but a limitation of flow rate in the pack area. Calculations show that the flow conductivity of a 5 mm fracture will decreased to 0.1% of the original after particle-filling. The particles filled into the annulus between the screens and the borehole wall can limit the axial annulus flow enormously, replaces the traditional packer sealing. The particles filled into the fractures will reduce the flow conductivity sharply, and no need to concern about the channeling inside the fractures and caves interwoven. Inflow-control devices are utilized to control radius flow rate and balance the production profile near well. The novel water-control method obtained the outstanding application results especially in the limestone reservoir, with the function of deep production profile control combined with wellbore water control, has the advantage of both chemical water shut-off and mechanical water-control methods.Successful application in reef limestone reservoir demonstrates the excellent feasibility of this novel water-control method. The oil rate increased 3.9 times after application to well A4A in Liuhua oil field South China Sea. For well A3, the initial water-cut is only one third of the average value compared with wells drilled in recent years at the same layer.It is found that the production effect of oil wells is positively correlated with overfilling amount. For higher overfilling amount, filling process optimization is carried out, and micro-fracturing is formed by increasing filling rate to the target reservoir. The max filling rate of oil well reached 292% by the improvement of filling technology.

Determination of peracetic acid in the presence of hydrogen peroxide based on the catalytic oxidation of ABTS

Determination of the concentration of peracetic acid (PAA) in the presence of H2O2 is a great challenging problem due to the similar chemical behaviors of the two species. In this study, we developed a new method for simultaneous measurement of PAA (0.5 – 10.0 μM) and total peroxides (i.e., PAA and H2O2 with a molar ratio of 10:6.5), based on the catalytic oxidation of ABTS by separately using Co(II) and peroxidase (POD) as the catalysts. Owing to the unique catalytic activity of Co(II) towards PAA, the coexistent H2O2 exhibits negligible effect on the determination of PAA. The value of absorbance at 415 nm increases linearly with increasing the concentration of PAA or total peroxides, and the sensitivities for PAA and total peroxides are as high as 5.31 × 104 and 9.07 × 104 M−1 cm−1, respectively. In addition, the proposed ABTS method shows excellent feasibility and applicability, which make it suitable to be employed for detection in complicated water matrices.

Amorphous Ni(OH)2 nano-boxes as a high performance substrate for aptasensor application

Recently, the performance of aptasensors has been significantly improved when combined with new nanomaterials. Herein, the amorphous Ni(OH)2 nano-boxes with intact shell structure were synthesized and, then, were used as an efficient substrate for covalent immobilization of the NH2-functionalized aptamer to develop label-free electrochemical aptasensor ​for ultrasensitive analysis of trypsin. This multidimensional hollow structure places a large amount of surface area in a small space of electrode surface and, thus, increasing the loading of the aptamer strings which significantly increases the sensitivity of ​measurement. A good linear relationship was found between logarithmic value of trypsin and Rct from 1 fg mL−1 to 500 ng mL−1 with a low detection limit of 0.3 fg mL−1. Furthermore, the proposed aptasensor showed good reproducibility, high stability and excellent feasibility in biological samples. This study showed that the Ni(OH)2 nano-boxes nanocomposite have various advanced electrochemical properties making them suitable electrode materials for aptasensor application.