Isolation Technology Research Articles

Experimental and numerical analysis of interface cohesive behavior on the viscoelastic damper under shear loading

The viscoelastic (VE) damper has been widely employed in isolation technology to mitigate the vibrations of engineering structures induced by earthquakes or winds. The VE damper is composed of steel plates and VE material which are chemically adhesive at contact surfaces and vulcanized through a high temperature. The performance degradation at the interface between the steel plate and VE material has a great impact on the mechanical properties of the VE damper at finite shear displacement and deserves more in-depth studies. In this work, the three-dimensional refined numerical model of the VE damper based on the bi-linear cohesive constitutive law is developed using the finite element software Abaqus. Experimental validations indicate the high feasibility of the developed model to represent the stiffness degradation behaviors of the VE damper under shear loading. The present work demonstrates the effectiveness of bi-linear cohesive constitutive law in dealing with the interface characteristics of the VE damper, and the wide application perspective of the developed model in engineering practice.

Strengthening Digital Marketing Security Website Threat Isolation and Protection Using Remote Browser Isolation Technology

Strengthening Digital Marketing Security Website Threat Isolation and Protection Using Remote Browser Isolation Technology

Influence of seismic isolation on the earthquake response of internal components in a fast reactor

Nuclear energy is being considered as a frontrunner towards achieving the zero carbon goal. A sustainable use of nuclear energy is possible when a reactor design is deployed across regions with varying seismic hazard. Seismic isolation technology has been proven to reduce earthquake loads in the structures, and is being seen as a key towards the standardized reactor designs. This paper investigates the influence of seismic isolation on the response of a generic fast reactor (GFR) similar to the prototype fast breeder reactor (PFBR) currently under commissioning at Kalpakkam, India. This reactor comprises a head-supported main vessel that houses other reactor components (e.g., core, inner vessel). The major vessels of the reactor are partially filled with liquid sodium. In order to understand the influence of seismic isolation, simplified lumped mass stick models (LMSMs) for the GFR components were developed. These models were based on static analysis results obtained using corresponding finite element (FE) models. The component models were assembled to generate the LMSM and FE model for the GFR. The LMSM was verified through the comparison of dynamic properties obtained using the FE model, and through the comparison of response-history analysis results. These models considered fluid masses lumped at respective shells, thereby ignoring the fluid–structure interaction (FSI) effects. A representative system was analyzed with and without considering FSI effects. These effects did not influence acceleration response significantly. Fixed-base (FB) and isolated base (IB) configurations of the LMSM for the GFR were subjected to a series of response-history analyses. Seismic isolation led to a substantial reduction (e.g., up to 10 times) in the median floor accelerations, particularly for lower sliding friction and longer sliding period. The floor spectral ordinates for the IB configuration of GFR subjected to 1.00 g shaking were less than that for the FB configuration of GFR subjected to 0.25 g shaking at most periods, suggesting that the PFBR can be deployed at locations with seismic hazard much greater than that at Kalpakkam if suitable isolation systems are used.

Implementation of a coupled FEM-SBFEM for soil-structure interaction analysis of large-scale 3D base-isolated nuclear structures

Accurately simulating the radiation damping of an infinite domain is a crucial issue for reasonably and effectively evaluating the isolation effect of three-dimensional (3D) base-isolated nuclear structures considering soil-structure interaction (SSI). The scaled boundary finite element method (SBFEM) has excellent advantages that enable it to precisely fulfil the radiation conditions. In this study, the finite element method (FEM) and SBFEM were combined to develop a coupled FEM-SBFEM technology. The structure and finite domain were discretized using FEM, and the infinite soil was realised using SBFEM. A complete and efficient calculation procedure for SSI analysis was developed based on the coupled FEM-SBFEM, improving the calculation efficiency through parallel programming. The accuracy of the developed procedure was verified using a numerical example. Furthermore, the dynamic response of a large-scale refined 3D base-isolated reactor building considering SSI was analysed using the proposed method. The results demonstrate that the 3D base isolation technology has excellent isolation performance. Additionally, we compared the response results of the proposed coupled FEM-SBFEM and direct method. The proposed procedure has broad engineering applicability and can be used for seismic SSI analysis of large-scale nuclear structures while maintaining high computational accuracy and stability.

Alongwind and crosswind response of friction-pendulum base-isolated high-rise buildings

Base isolation technology is widely accepted as an effective strategy for the seismic design of buildings. Although the elastomeric isolator is still extensively adopted for the base-isolation system in practice, there is a trend to use the frictional pendulum bearing (FPB) due to its high vertical bearing capacity, stable performance and good recentering capability. In this paper, the dynamic response of base-isolated high-rise buildings with FPB having a velocity-dependent friction coefficient subjected to uncoupled alongwind and crosswind loads is studied. The response characteristics calculated from response history analysis (RHA) are analyzed. Meanwhile, two statistical linearization methods are utilized to estimate the standard deviation (STD) of the structural response and to obtain the equivalent parameters of the linearized system. The time-varying mean of the base displacement under alongwind load with a non-zero mean is also discussed by the linearization method. Finally, a parameter analysis of the isolation bearing is performed to investigate the effects of the radius and friction coefficient of the sliding plate on the wind-induced vibration. This study highlights the strong nonlinear response characteristics of base-isolated high-rise buildings with FPB and offers design guidelines under strong winds.

Implementation of the multielectrode radiofrequency-balloon in real-world clinical practice-operator learning curve and procedural outcome at a high-volume center.

The novel multielectrode radiofrequency (RF) balloon catheter (HELIOSTAR™, Biosense Webster) is a new technology for pulmonary vein isolation (PVI) in atrial fibrillation (AF), combining RF-ablation and 3D-mapping visualization with the concept of a "single-shot"-ablation device. This study evaluates the operator learning curve und procedural outcome during implementation of the multielectrode RF-balloon at a high-volume center. The first 40 patients undergoing PVI by multielectrode RF-balloon catheter at Heidelberg University Hospital were included in this prospective study. Procedural outcome was analyzed over the course of increasing experience with the device. 157/157 pulmonary veins (PVs) were successfully isolated with the RF-balloon catheter, in 73.2% by a single RF-application. Median time to isolation (TTI) was 11.0 s (Q1 = 8.0 s; Q3 = 13.8 s). Median procedure time was 62.5 min (Q1 = 50.0 min; Q3 = 70.5 min). LA-dwell time was 28.5 min (Q1 = 23.3 min; Q3 = 36.5 min). Median fluoroscopy duration was 11.6 min (Q1 = 10.1 min; Q3 = 13.7 min). No serious procedure-related complications were observed, apart from one case of unclear, post-procedural acute-on-chronic kidney injury. With increasing operator experience, an additional reduction in procedure duration was observed. Rapid implementation of a "single shot"-ablation device combining RF-ablation and 3D-mapping can be achieved with high acute procedural efficacy and safety at a high-volume center. Previous experience with "single-shot" ablation devices may be advantageous for time-efficient introduction of the novel RF-balloon catheter into clinical practice. ClinicalTrials.gov; Identifier NCT0560361.

Seismic Performance Analysis of the Two-Dimensional Isolation Device for Double-Layer Grid Structure

The isolation technologies are adopted to protect the long-span space structures from serious damage under the action of earthquakes. When the isolation system is applied to the space structures, both horizontal and vertical vibration control effects on the structures should be concerned. In this paper, a two-dimensional earthquake isolation and mitigation device (TEIMD) composed of a high-damping viscoelastic (VE) core pad and VE dampers is proposed. Based on the dynamic shear experiment results of the VE damper, the energy dissipation capability of VE material is preferable. Then, the nonlinear equivalent stiffness and equivalent damping ratio of the TEIMD in horizontal and vertical directions are evaluated by using the numerical simulation method. The TEIMDs are arranged on the column top of a double-layer grid structure to assess the isolation effectiveness of the novel device. The dynamic analysis results of the double-layer grid structure with and without TEIMD reveal that this novel device can significantly reduce the acceleration response of the upper grid by relying on the strong energy dissipation performances in the horizontal and vertical directions. This research also verifies the feasibility of applying the TEIMD to the double-layer grid structure, which can effectively dissipate the vertical vibration energy of the structure.

Correction to: SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

Correction to: SAP-sand mixtures as a geotechnical seismic isolation technology: from the dynamic characterization to a simple analytical design approach

Integration of single‐cell transcriptome and proteome technologies: Toward spatial resolution levels

AbstractCells are basic building blocks of life with vast heterogeneity. Nowadays, the rapid development of single‐cell multiomics (scMulti‐Omics) has facilitated comprehensive understanding of gene regulatory networks, cellular characteristics, and temporal dynamics. However, simultaneous analysis of transcriptome and proteome at single‐cell level still faces huge challenges due to their differences in molecular modalities. Recent technological advances in single‐cell manipulations, barcoding, and ultrasensitive instrument recently offer unprecedented opportunities for the co‐profiling of genes and proteins. In this review, multiple types of single‐cell isolation, lysis, and molecular separation technologies are first introduced. Second, various approaches for co‐measurement of transcriptome and proteome in single‐cells are summarized, with their advantages, limitations, and capacity for targeted or unbiased deep analysis. Then we highlight the cutting‐edge spatial multiomics methodologies that operate at the single‐cell or subcellular resolution level, providing a comprehensive understanding of cell function and heterogeneity within the tissue spatial environment. The emerging biomedical applications of multiomics are also discussed. Finally, the challenges and prospects of this field are proposed.

Preparation, Optimization, Compatibility Study of Captopril Proniosome, and In-vitro, In-vivo Evaluation of Release Study

Coagulation compartment isolation technology has also developed transdermal proteosome arrays using various non-ionic surfactants. Span-60 proteasomes have reduced HLB values, longer chains alkyl, and high transition temperatures, resulting in higher capture efficiency (84.14 ± 4.76). The addition of cholesterol LDL and lecithin also increased bilayer stiffness. The size of the vesicles decreases with his Tween method and multiplies with wingspan and consciousness. Low polydispersity index and high zeta capacity were observed in the arrangement of proteasomes. TEM studies confirm perfectly round niosomes. Infrared studies have confirmed that the vesicular form has no drug interactions and no drug is trapped. Proniosomes demonstrated slower release kinetics than controls. Captopril in 40% PEG. Additionally, the defined emission charge of span changes compared to Tween, which can be attributed to the lipophilicity of span and captopril. The release profile was observed for the Higuchi version, suggesting that drug introduction is diffusion controlled. The transdermal flux of captopril was highest for the span 60 system in isolated and closed rat skin.

An eco-sustainable innovative geotechnical technology for the structures seismic isolation, investigated by FEM parametric analyses

Geotechnical Seismic Isolation (GSI) is an innovative technique for protecting structures in earthquake-prone areas. The main idea is to improve the foundation soil so that seismic energy is partially dissipated within GSI before being transmitted to the structure. Among other materials proposed for foundation soil improvement, gravel-rubber mixtures (GRMs), with rubber grains manufactured from end-of-life tires, have attracted significant research interest thanks to their good mechanical properties. GRMs also represent a modern recycling system to reduce the stockpile of scrap tires worldwide. The present study investigated numerically the effect of a GRM layer located underneath the shallow foundations of a real structure. The structure is a typical reinforced concrete building in southern Italy. A Finite Element Modelling (FEM) was carried out to evaluate the overall static and dynamic behaviour of the soil-GRMs-structure system. Three FEM models were performed with and without the GRM layer, varying the GRM layer thickness and the seismic inputs. The comparisons among the models allow us to assess the performance of the GRM underneath the foundations as a new eco-sustainable solution for the seismic isolation of structures.

Ultrasound cavitation: a reliable non-enzymatic method for adipose-derived mesenchymal stem cell (ADSC) isolation

BackgroundAdipose tissue is known to serve as an abundant and readily accessible source of adipose-derived stem cells (ADSCs) as an alternative to bone marrow. Collagenase is one of the most widely used methods for the isolation of ADSCs from adipose tissue, but it takes a long time, and there are also debates about safety. We propose an ultrasonic cavitation-treated method that can significantly reduce time and avoid the problem of using xenogeneic enzymes in ADSCs isolation.MethodsADSCs were isolated from adipose tissue using the enzyme treatment method and the ultrasonic cavitation treatment method. Cell proliferation was measured using cell viability assay. The expression levels of the surface markers of ADSCs were estimated by real-time PCR. After, ADSCs were cultured in chondrogenic, osteogenic, or adipogenic differentiation medium; the differentiation potential of ADCSs was analyzed by Alcian blue, Alizarin Red S, Oil Red O, and real-time PCR.ResultsThe cells treated with collagenase and ultrasound had similar cell yields and proliferation after isolation. The difference in the expression of surface markers of ADSCs was not statistically significant. ADSCs showed differentiation potential into adipocytes, osteocytes, and chondrocytes, and there was no difference between the enzyme treatment method and the ultrasonic cavitation treatment method. The yield of the ADSC increased in time- and intensity dependently.ConclusionsUltrasound certainly serves as a promising method in advancing ADSC isolation technology.

Abstract PR013: Unlocking the proteome of metastatic prostate cancer circulating tumor cells

Abstract In recent years, liquid biopsies have emerged to provide improved insights on the current disease state of a patient, but they generally rely on a small number of protein markers from immunofluorescent staining or cell-free DNA, which provides limited information especially around drug targets. As more targeted therapies and immunotherapies enter the market, selecting the optimal drug target could improve patient outcomes drastically. One way to achieve this goal is to generate multi-omic datasets from the cancer cells in circulation, known as circulating tumor cells (CTCs). In this study, we collaborated with Astrin Biosciences and used their patented isolation technology to enrich CTCs with high purity from the blood of 15 metastatic castration resistant prostate cancer (mCRPC) patients. The enriched CTCs and a patient matched control sample consisting primarily of white blood cells were divided such that RNA and protein could be interrogated from the same patient. Label free unbiased mass spectrometry-based proteomics was used to identify the CTC-enriched proteins and marks the first time a global proteomic assessment has been performed on CTCs from cancer patients. Initial analysis identified over 1,500 peptides corresponding to greater than 500 proteins from each patients’ CTCs; including increased epithelial cell markers in the CTC-enriched sample and increased WBC markers in the control sample. Hallmarks of androgen response and detection of the androgen receptor were also identified in the CTC-enriched proteome. Overall, this study was designed to show the feasibility of obtaining large scale proteomic data from a liquid biopsy and future studies will provide more insight into the clinical utility of such data with a focus on cancer signaling mechanisms and biomarkers. Importantly, as we analyze more patients, we plan to compare the proteomic data with future RNA signatures across mCRPC patients to eventually be able to correlate them with drug response with the overall goal to improve treatment selection and patient outcomes. Citation Format: Justin M. Drake, Zoi Sychev, Alec Horrmann, Kaylee Judith Smith, Catalina Galeano-Garces, Ali Arafa, Nicholas Heller, Mahdi Ahmadi, Jiarong Hong, Megan Ludwig, Justin Hwang, Emmanuel S. Antonarakis, Jayant Parthasarathy. Unlocking the proteome of metastatic prostate cancer circulating tumor cells [abstract]. In: Proceedings of the AACR Special Conference: Advances in Prostate Cancer Research; 2023 Mar 15-18; Denver, Colorado. Philadelphia (PA): AACR; Cancer Res 2023;83(11 Suppl):Abstract nr PR013.

A Closed-system Technology for Mechanical Isolation of High Quantities of Stromal Vascular Fraction from Fat for Immediate Clinical Use.

SVF cells were isolated from the same lipoaspirate sample (n = 30) by enzymatic isolation, massive shaking (wash), or engine-induced RBs mechanical isolation. SVF cells were counted, characterized by flow cytometry and by their ability to form adipose-derived stromal cells (ASCs). The RBs mechanical approach yielded 2 × 105 SVF nucleated cells/mL fat, inferior to enzymatic isolation (4.17 × 105) but superior to cells isolating from fat by the "wash" technique (0.67 × 105). Importantly, RBs SVF isolation yield was similar to reported yields achieved via clinical-grade enzymatic SVF isolation. RBs-isolated SVF cells were found to contain 22.7% CD45-CD31-CD34+ stem cell progenitor cells (n = 5) yielding quantities of multipotent ASCs similar to enzymatic controls. The RBs isolation technology provided for rapid (<15 min) isolation of high-quality SVF cells in quantities similar to those obtained by enzymatic digestion. Based on the RBs platform, a closed-system medical device for SVF extraction in a rapid, simple, safe, sterile, reproducible, and cost-effective manner was designed.

WATER PRODUCTION ISOLATION TECHNIQUES FOR OIL-WELLS WITH HIGH RESERVOIR TEMPERATURE

Advanced drilling technology makes it possible to penetrate oil and gas sites with deep bedding of oil reservoir, a complex multi-layer structure and a high reservoir temperature at the well bottom, reaching 150°C. The difficult geology of oil strata leads to the fact that the productive layers of a well are flooded unevenly. In this work the causes for water cut in reservoirs are given, repair and insulation work and technologies for isolation of water-bearing intervals in the oil-producing wells considered. Grouting composites for water inflow limitation in reservoirs with low temperature (up to 100°C) and high-temperature reservoirs are studied. For water flood control in the oil and gas wells with high temperature viscoelastic composites with extended gel-time and high stable strength and adhesive properties has been proposed. The advantage of polymer-based composites is their kinetic behavior in dynamic mode, when filtering in a porous medium, which makes it possible to isolate effectively intake formations with different channel openings with a small flow rate of the mixture.

Study of the adjuvant properties of preparations containing recombinant human granulocyte-macrophage colony stimulating factor

The relevance of the search for new vaccine adjuvants is growing along with the increase in the number of current vaccine preparations, especially those developed on the basis of proteins. Some cytokines are known to exert adjuvant properties. The present work is devoted to the study of adjuvant activity of recombinant human granulocyte-macrophage colony stimulating factor (rhGM-CSF) and constructs based on it. Earlier, we developed a technology for isolation and purification of GM-CSF from the E. coli SG20050/p280_2GM producer strain, as well as a technology for conjugating polyglucin:spermidine complexes with rhGM-CSF. Double-stranded RNA was used to obtain molecular constructs on the basis of rhGM-CSF conjugate. To assemble constructs, the ratio of the components was calculated for one dose of the preparation to contain 5-40 mg of rhGM-CSF and 100 mg of double-stranded RNA. The effectiveness of the formation of molecular constructs was evaluated by dsRNA electrophoretic mobility shift in a 1% agarose gel. The effectiveness of the resulting adjuvants was determined in ELISA assays by measuring the titers of specific antibodies in mouse sera against ovalbumin or recombinant receptor-binding domain of the surface S protein of the severe acute respiratory syndrome coronavirus 2 (Delta variant (B.1.617.2). The experiments were carried out in 100 male BALB/c mice weighing 16-18 g. Mice were immunized twice, with a 14-day interval, by intramuscular injection of 200 mL per animal. Recombinant receptor-binding domain of the surface protein of SARS-CoV-2 was administered at a dose of 50 mg/animal, ovalbumin – at two doses – 1 mg or 5 mg/animal. Corresponding antigen was used as a positive control, a saline solution – as a negative control. It was shown that the maximum effect was achieved by immunization with a construct based on double-stranded RNA and rhGM-CSF conjugated to polyglucin-spermidine. The use of a conjugate without double-stranded RNA as an adjuvant also improved humoral response. The use of native rhGM-CSF did not increase the titers of specific antibodies. Thus, it was found that rhGM-CSF being a part of a polysaccharide conjugate or a molecular construct exerted an ability to enhance the humoral immune response to protein antigens.

Research and optimization design of dual-frequency vibration isolation system for helicopter reducer

Dynamic antiresonance vibration isolation technology is widely used in the vibration reduction system of helicopters, because its simple structure and high vibration isolation efficiency. In this study, a dual-frequency vibration isolation system with two anti-resonant frequencies has been established, which can adapt to the vibration characteristics of two main vibration frequencies caused by the variable speed of the new high-speed helicopter. The theoretical equation and transmissibility of the dual-frequency vibration isolation system are derived, and the variation law of the weight and other relevant parameters on the vibration isolation performance is explored. The accuracy of the theoretical results is verified by model tests. According to the installation form of the helicopter reducer, the structure of the dual-frequency vibration isolation system is preliminarily optimized, which provides technical support for the design of the vibration isolator of the helicopter with variable speed.

Polarization insensitive multiband metasurface absorber for L, C, and X band applications

An ultrathin, multiband, polarization insensitive with wide angle stability metasurface absorber having unitcell dimension is proposed ( is the free space wavelength at 1.6 GHz). The four-fold symmetry of the unitcell makes it insensitive to TE and TM polarizations. This metasurface follows the sub-quarter wavelength thickness including an air gap of 2.5 mm and metal backing. The proposed unitcell of the metamaterial absorber (MMA) is designed by parametric optimization and has absorption peaks in L, C, and X bands. This absorber is suitable for applications like radar cross section reduction, isolation, and stealth technologies. The lumped SMD resistors are used to enhance absorption peaks simultaneously in all bands mentioned above. This metasurface has absorptivity of 95%, 99%, 97% & 94% at 1.6 GHz, 5 GHz, 7.5 GHz and 10.2 GHz respectively. This is a polarization-insensitive absorber showing stable absorption for different incidence angles between and at the above-given frequencies. The absorption effect has been studied by investigating the filter effect from the equivalent circuit modeling using surface current distribution and normalized impedance. The proposed structure has been fabricated and its measurement results agree well with the simulated one.

A mammalian cell display platform based on scFab transposition.

In vitro display technologies have been successfully utilized for the discovery and evolution of monoclonal antibodies (mAbs) for diagnostic and therapeutic applications, with phage display and yeast display being the most commonly used platforms due to their simplicity and high efficiency. As their prokaryotic or lower eukaryotic host organisms typically have no or different post-translational modifications, several mammalian cell-based display and screening technologies for isolation and optimization of mAbs have emerged and are being developed. We report here a novel and useful mammalian cell display platform based on the PiggyBac transposon system to display mAbs in a single-chain Fab (scFab) format on the surface of HEK293F cells. Immune rabbit antibody libraries encompassing ~7×107 independent clones were generated in an all-in-one transposon vector, stably delivered into HEK293F cells and displayed as an scFab with rabbit variable and human constant domains. After one round of magnetic activated cell sorting and two rounds of fluorescence activated cell sorting, mAbs with high affinity in the subnanomolar range and cross-reactivity to the corresponding human and mouse antigens were identified, demonstrating the power of this platform for antibody discovery. We developed a highly efficient mammalian cell display platform based on the PiggyBac transposon system for antibody discovery, which could be further utilized for humanization as well as affinity and specificity maturation.

Pulmonary vein isolation and additional selective ablation of low voltage areas and atrial late potentials for persistent atrial fibrillation (SOLVE-AF-Study)

Abstract Funding Acknowledgements Type of funding sources: Private company. Main funding source(s): Abbott Introduction Novel catheter ablation technologies (e.g. RF with contiguous lesions) for pulmonary vein isolation (PVI) achieve high (80-85%) arrhythmia freedom rates at 12 months in both paroxysmal and persistent AF. However, success rates are importantly reduced (45-50%) in persistent AF patients presenting atrial cardiomyopathy with additional low voltage areas in the left atrial body. Aim SOLVE-AF study is a prospective randomized multicenter study, in which the standard approach "circumferential PVI" is compared to "additional ablation of low voltage areas and ablation of slow conducting "atrial late potentials (ALPs)" during sinus rhythm (SR)". Methods 320 patients with persistent AF will be included. Patients undergo left atrial high definition voltage mapping in SR. 160 patients with low voltage areas (&amp;lt;0.5mV at &amp;gt;5cm2) within the LA body will be randomized to "circumferential-PVI" vs. "additional low-voltage-guided ablation". The remaining 160 without low voltage substrate (registry group) will undergo "circumferential-PVI". Arrhythmia recurrences (defined as AF/AT &amp;gt;30 sec) will be assessed at 6 and 12 months (7-day-Holter and event-recorder) following ablation therapy (top panel). Results Currently, 120 patients have been included into the registry group and 120 patients with low voltage substrate have been randomized. Results of the SOLVE-AF-pilot study including a total of 210 patients (110 registry patients without LA-LVS and 100 patients with LA-LVS who were assigned to PVI-only versus additional substrate-based ablation) at the University-Heart-Center-FR-BK favor "PVI plus substrate-based ablation" in those patients who do present significant low voltage areas (see KM-curve bottom panel). Conclusions Results from the pilot trial suggests improved arrhythmia freedom rate with PVI plus additional substrate-based ablation during sinus rhythm. Final results of the prospective randomized multi-center trial SOLVE-AF are expected in June 2024.