Matrix Interactions Research Articles

Coagulation factor II thrombin receptor as a promising biomarker in breast cancer management.

This study aims to comprehensively investigate the role of coagulation factor II thrombin receptor (F2R) in breast cancer (BC) and to evaluate its potential as a biomarker in this context. Data on female BC were retrieved from the TCGA database. Comparative analyses were performed, including enrichment analysis, tumor immune microenvironment analysis, drug sensitivity testing, molecular docking, and cell-based experiments, to assess the expression and function of F2R in BC. Statistical analyses and graphical representations were conducted using R software. The study confirmed a significant upregulation of F2R in BC, which was associated with a more favorable prognosis. Clinical correlation analysis revealed a strong association between F2R expression and key clinical parameters, such as estrogen receptor and progesterone receptor status. Additionally, genes co-expressed with F2R were significantly linked to various biological processes, including cell cycle regulation, oxidative phosphorylation, ribosomal function, and extracellular matrix interactions. F2R also showed associations with immune modulators, particularly CD200 and NRP1. Drug sensitivity analysis, molecular docking, and cell experiments consistently demonstrated positive correlations between F2R expression and sensitivity to dasatinib. This study underscores the potential of F2R as a valuable biomarker in BC, providing insights into the molecular mechanisms underlying tumorigenesis.

Influence of Silane‐Treated Jute/Kenaf Fibers on the Mechanical Properties of Polymer Composites for Biomedical Applications: Optimization Using RSM and ANN Approaches

ABSTRACTThis study investigates the effect of silane‐treated jute/kenaf fibers on the flexural and hardness properties of polymer composites for potential biomedical applications, such as prosthetics and bio‐implants. Using response surface methodology (RSM) and artificial neural network (ANN), the optimal combination of nanoparticle percentage, silane concentration, and silane dipping duration was identified to enhance the mechanical properties of the composites. RSM, coupled with analysis of variance (ANOVA), evaluated the influence of these variables on composite performance, revealing that silane treatment significantly improved flexural strength, while all fiber‐related variables impacted both flexural strength and hardness. The silane dipping duration emerged as the most influential factor, with nanoparticle addition enhancing fiber–matrix interactions and promoting better agglomeration. The ANN model accurately predicted the composite's properties, with results strongly correlating to experimental data. The optimized formulation, consisting of 5% nanoparticle content, 10% silane treatment, and a 20‐min silane dipping duration, demonstrated a 26.22% increase in flexural strength and a 33.15% improvement in hardness. This optimized composite formulation holds promise for use in biomedical applications requiring high mechanical strength and durability, such as in prosthetic materials and orthopedic implants, where enhanced flexural strength and hardness are critical for longevity and performance.

The Characteristics of Resin Waste (RW)/Recycled High-Density Polyethylene (R-HDPE) Blends to Enhanced Pavement

Permeable pavement is characterized by open cell structures that enable the drainage of rainfall and snowmelt, as opposed to the runoff observed on impervious pavements. The structural strength of commercial permeable pavement materials is lower than that of conventional pavements due to inherent permeability and structural distinctions. This research focuses on the fabrication of samples using a combination of Resin Waste (RW) and reinforced Recycled High-Density Polyethylene (R-HDPE) in varying ratios of RW (30%, 40%, 50%, 60% and 70% wt/wt). The fabrication process involves a 3-hour heating process at 200°C in a furnace, followed by a 24-hour cure at room temperature. Physical and mechanical properties of the RW/R-HDPE Blends were examined, revealing that the 60% R-HDPE ratio resulted in the lowest density (4.523 g/cm3) and porosity (0.246%). SEM images displayed fewer voids, indicating effective filler dispersion and resin matrix interaction at the 60% resin waste ratio. Tensile strength and stiffness elasticity were maximized at 60% wt/wt of R-HDPE, reaching 3.36 MPa, while the bending strength peaked at 1.1 MPa at the same ratio. The 60% RW/R-HDPE ratio recorded the highest impact strength (26.25 kJ/m2) and energy absorption (1.69 J), showcasing the sample's ability to absorb impact energy through controlled failure mechanisms. In conclusion, the 60% wt/wt RW/R-HDPE Blends exhibit promising potential for enhancing the properties of permeable pavement, particularly in road applications, due to its superior bending and tensile strength.

Promotion effect of nitrogen doping on the low-temperature NH3-SCR of NO over activated carbon: Characterization and mechanism analysis

Heteroatom nitrogen doping in carbon catalysts is recognized an effective strategy for tailoring the properties of carbon catalysts for various flue gas de-NOx applications. However, accurately discerning the active structures after nitrogen doping and elucidating the promotion effect on low-temperature selective catalytic reduction activity remains a formidable challenge under different nitrogen doping preparation conditions. In this study, a series of nitrogen-doped activated carbon catalysts was synthesized through the L16(45) orthogonal array design method, and the degree of influence of various preparation conditions on de-NOx catalytic activities was also assessed. The optimal preparation conditions determined by range analysis were employed to synthesize NOAC-17, achieving the NO conversion of 95% and N2 selectivity of 99% at 300 °C, respectively. Subsequently, various characterization results proved that nitrogen doping induced the formation of abundant basic groups. The imine, amide, amine, and N-6 groups altered the acid-base of the activated carbon surface and increased the adsorption of acidic NOx. The N-5 and N-Q groups enhanced electronic interaction in the carbon matrix and accelerated electron mobility in the catalytic reaction process. Moreover, the N-6 group played multiple roles beyond the aforementioned effect due to its special structure. It also enhanced the accumulation of oxygen vacancies, which were closely associated with further oxidation of adsorbed NO. The lone electron pair in the N-6 group within the activated carbon framework can alter the polarity of the catalyst, thereby exerting a positive influence on the adsorption and activation of NH3. The nitrogen-doped catalyst identified through range analysis of the orthogonal experiment primarily facilitated the NH3-SCR reaction via the E-R mechanism with supplementary contribution from L-H mechanism at low temperatures. The nitrogen doping conditions obtained for the activated carbon catalyst provide valuable insights for the strategic enhancement of its catalytic performance in low-temperature NH3-SCR reactions.

Mictlan-D3: A novel medium sized RGD-Disintegrin obtained from Crotalus mictlantecuhtli venom, in vitro tested against human breast Cancer and endothelial cells

Disintegrins are small non-enzymatic proteins present often at low concentration in the venom of viperid snakes. Isolated disintegrins are known for their lack of toxicity as well as their capacity to antagonize integrin receptors. Integrins are a major family of heterodimeric cell surface receptors that mediate cell-cell and cell-extracellular matrix (ECM) interactions. Integrins regulate key functions in cancer pathology and also tumor development. The aim of this study consisted in the isolation and characterization of disintegrins from rattlesnake new species Crotalus mictlantecutli venom. A disintegrin fraction obtained by RP-HPLC and named mictlan-D3, consist in two isoforms of 7439 and 7509 Da with 72 amino acid sequence containing the RGD binding motif. Mictlan-D3 inhibited MDA-MB-231 and HMEC-1 cell adhesion to laminin (LN), fibronectin (FN) and vitronectin (VN), highest inhibition was on MDA-MB-231 cell adhesion to LN by 81 % at 1 μM. The blockade of ⍺Vβ3 integrin was evaluated by wound healing migration assay. Mictlan-D3 inhibited MDA-MB-231 cell migration by 80 % and 38 % after 24 and 72 h of incubation respectively. HMEC-1 cell migration was inhibited by 67.6 % and 27.9 % after 24 and 72 h of incubation. Additionally, mictlan-D3. This work represent the first characterization of disintegrins from the Crotalus mictlantecutli venom.

Incremental Deformations and Bifurcation of Elastic Solids Reinforced by Fibers With Intrinsic Extensional, Flexural, and Torsional Elasticity

Abstract We present a model for incremental deformations of an elastic solid reinforced by a single family of fibers that offer resistance to extension, flexure, and torsion. The theory is cast in the setting of small-on-large deformations and provides a framework for the multiscale analysis of bifurcation of equilibria in fibrous composites. The model is based on a theory of three-dimensional Cosserat elasticity in which fiber kinematics are controlled by a rotation field that is weakly coupled to the bulk deformation through a pointwise fiber-materiality constraint. Fiber–matrix interaction forces are explicitly accounted for via the attendant Lagrange multipliers. We demonstrate the utility of the model by investigating the onset of bifurcation in an incompressible fiber-reinforced elastic half-plane. In particular, we study the influence of axial fiber stiffness, flexural stiffness, and fiber–matrix interaction forces on planar buckling modes. We envisage a model for the study of buckling problems of biological and industrial relevance with a view to gaining better insight into the roles of fiber bending, twisting, and fiber–matrix interaction forces in regulating the buckling of fibrous composites.

An annotated biobank of triple negative breast cancer patient-derived xenografts featuring treatment-naïve and longitudinal samples throughout neoadjuvant chemotherapy.

Triple negative breast cancer (TNBC) that fails to respond to neoadjuvant chemotherapy (NACT) can be lethal. Developing effective strategies to eradicate chemoresistant disease requires experimental models that recapitulate the heterogeneity characteristic of TNBC. To that end, we established a biobank of 92 orthotopic patient-derived xenograft (PDX) models of TNBC from the tumors of 75 patients enrolled in the ARTEMIS clinical trial ( NCT02276443 ) at MD Anderson Cancer Center, including 12 longitudinal sets generated from serial patient biopsies collected throughout NACT and from metastatic disease. Models were established from both chemosensitive and chemoresistant tumors, and nearly 30% of PDX models were capable of lung metastasis. Comprehensive molecular profiling demonstrated conservation of genomes and transcriptomes between patient and corresponding PDX tumors, with representation of all major transcriptional subtypes. Transcriptional changes observed in the longitudinal PDX models highlight dysregulation in pathways associated with DNA integrity, extracellular matrix interactions, the ubiquitin-proteasome system, epigenetics, and inflammatory signaling. These alterations reveal a complex network of adaptations associated with chemoresistance. This PDX biobank provides a valuable resource for tackling the most pressing issues facing the clinical management of TNBC, namely chemoresistance and metastasis.

Multi-output discrete grey model tailored for electricity consumption forecast

To address the limitation of many conventional grey forecasting methods that prioritize temporal dynamics analysis while often overlooking the essential spatial characteristics, we developed a multi-output discrete grey model tailored for forecasting electricity consumption in China's Yangtze River Delta, incorporating spatial effects. Specifically, we design a dynamic spatial interaction matrix to precisely capture the spatial correlations among neighboring areas, and integrate multiple sets of fixed-effect parameters to adeptly address spatial heterogeneity. Additionally, we implement regularization technique to prevent overfitting and utilize the Bayesian Optimization algorithm for hyper-parameter adjustment, considerably enhancing the model's stability of parameter estimation and its resilience to noise. Finally, a comprehensive case study, benchmarked against seven other models, highlights our model's outstanding multi-step predictive accuracy and robustness against input data uncertainty, exceeding the performance of existing methods.

MatrixDB 2024: an increased coverage of extracellular matrix interactions, a new Network Explorer and a new web interface.

MatrixDB, a member of the International Molecular Exchange consortium (IMEx), is a curated interaction database focused on interactions established by extracellular matrix (ECM) constituents including proteins, proteoglycans, glycosaminoglycans and ECM bioactive fragments. The architecture of MatrixDB was upgraded to ease interaction data export, allow versioning and programmatic access and ensure sustainability. The new version of the database includes more than twice the number of manually curated and experimentally-supported interactions. High-confidence predicted interactions were imported from the Integrated Interactions Database to increase the coverage of the ECM interactome. ECM and ECM-associated proteins of five species (human, murine, bovine, avian and zebrafish) were annotated with matrisome divisions and categories, which are used for computational analyses of ECM -omic datasets. Biological pathways from the Reactome Pathway Knowledgebase were also added to the biomolecule description. New transcriptomic and expanded proteomic datasets were imported in MatrixDB to generate cell- and tissue-specific ECM networks using the newly developed in-house Network Explorer integrated in the database. MatrixDB is freely available at https://matrixdb.univ-lyon1.fr.

Prolonged cultivation enhances the stimulatory activity of hiPSC mesenchymal progenitor-derived conditioned medium

BackgroundHuman induced pluripotent stem cells represent a scalable source of youthful tissue progenitors and secretomes for regenerative therapies. The aim of our study was to investigate the potential of conditioned medium (CM) from hiPSC-mesenchymal progenitors (hiPSC-MPs) to stimulate osteogenic differentiation of human bone marrow-derived mesenchymal stromal cells (MSCs). We also investigated whether prolonged cultivation or osteogenic pre-differentiation of hiPSC-MPs could enhance the stimulatory activity of CM.MethodsMSCs were isolated from 13 donors (age 20–90 years). CM derived from hiPSC-MPs was added to the MSC cultures and the effects on proliferation and osteogenic differentiation were examined after 14 days and 6 weeks. The stimulatory activity of hiPSC-MP-CM was compared with the activity of MSC-derived CM and with the activity of CM prepared from hiPSC-MPs pre-cultured in growth or osteogenic medium for 14 days. Comparative proteomic analysis of CM was performed to gain insight into the molecular components responsible for the stimulatory activity.ResultsPrimary bone marrow-derived MSC exhibited variability, with a tendency towards lower proliferation and tri-lineage differentiation in older donors. hiPSC-MP-CM increased the proliferation and alkaline phosphatase activity of MSC from several adult/aged donors after 14 days of continuous supplementation under osteogenic conditions. However, CM supplementation failed to improve the mineralization of MSC pellets after 6 weeks under osteogenic conditions. hiPSC-MP-CM showed greater enhancement of proliferation and ALP activity than CM derived from bone marrow-derived MSCs. Moreover, 14-day cultivation but not osteogenic pre-differentiation of hiPSC-MPs strongly enhanced CM stimulatory activity. Quantitative proteomic analysis of d14-CM revealed a distinct profile of components that formed a highly interconnected associations network with two clusters, one functionally associated with binding and organization of actin/cytoskeletal components and the other with structural constituents of the extracellular matrix, collagen, and growth factor binding. Several hub proteins were identified that were reported to have functions in cell-extracellular matrix interaction, osteogenic differentiation and development.ConclusionsOur data show that hiPSC-MP-CM enhances early osteogenic differentiation of human bone marrow-derived MSCs and that prolonged cultivation of hiPSC-MPs enhances CM-stimulatory activity. Proteomic analysis of the upregulated protein components provides the basis for further optimization of hiPSC-MP-CM for bone regenerative therapies.Graphical

Enhancing enset fiber‐reinforced polylactic acid composites through different surface treatments for emerging applications

AbstractEnvironmental concerns and the over‐exploitation of natural resources have driven the search for eco‐friendly materials. Agro/industrial waste, often discarded, can be repurposed as fillers in biocomposites. However, bio‐fibers present challenges such as poor compatibility, high moisture absorption, and variable mechanical properties. This study examines various fiber surface modification techniques, including NaOH, silane, alkali‐silane, and pectinase enzyme treatments on enset fiber (EF) to produce sustainable reinforced poly(lactic acid) (PLA) composites. Untreated EF/PLA composites were fabricated for comparison. Results showed that the applied EF surface treatments, especially using pectinase enzyme, significantly enhanced mechanical, thermal, and thermomechanical properties. Pectinase‐treated EF/PLA composites displayed increased tensile strength by 55.99%, elongation at the break by 39.49%, tensile modulus by 32.59%, impact strength by 51.50%, flexural strength by 51.85%, flexural modulus by 60.90%, and improved thermal stability as compared to untreated composite. Scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analyses verified better fiber‐matrix interaction with clarity due to reduced non‐cellulosic components. Pectinase enzyme treatment emerged as the most effective, eco‐friendly method, enhancing the enset fiber's potential in polymer biocomposites, suitable for automotive interiors and packaging industries, reducing synthetic plastic pollution, and utilizing agricultural waste.Highlights Enset fibers were modified by NaOH, silane, NaOH/silane, and pectinase enzyme The modified enset/PLA composites were prepared by compression molding Surface treatments enhanced the enset‐PLA matrix interaction Pectinase‐modified enset/PLA composite showed superior properties Improved properties of enset composites make it ideal for various applications

Impressions of Parton Distribution Functions

Abstract Parton distribution functions (DFs) have long been recognised as key measures of hadron structure. Today, theoretical prediction of such DFs is becoming possible using diverse methods for continuum and lattice analyses of strong interaction (QCD) matrix elements. Recent developments include a demonstration that continuum and lattice analyses yield mutually consistent results for all pion DFs, with behaviour on the far valence domain of light-front momentum fraction that matches QCD expectations. Theory is also delivering an understanding of the distributions of proton mass and spin amongst its constituents, which varies, of course, with the resolving scale of the measuring probe. Aspects of the pion DF and proton spin developments are sketched herein, along with some novel perspectives on gluon and quark orbital angular momentum.

Viscosity regulates cell spreading and cell-extracellular matrix interactions.

Fluid viscosity and osmolarity are among some of the underappreciated mechanical stimuli that cells can detect. Abnormal changes of multiple fluidic factors such as viscosity and osmolarity have been linked with diseases such as cystic fibrosis, cancer, and coronary heart disease. Changes in viscosity have been recently suggested as a regulator of cell locomotion. These novel studies focus on cell migration and spreading on glass substrates and through microchannels, and it remains a question whether viscosity impacts the cellular remodeling of extracellular matrices (ECMs). Here, we demonstrate that elevated viscosity induces cellular remodeling of collagen substrates and enhances cell spreading on ECM-mimetic substrates. Our results expand on recent work showing that viscosity induces increased cellular forces and demonstrates that viscosity can drive local ECM densification. Our data further show that microtubules, Ras-related C3 botulinum toxin substrate 1 (Rac1), actin-related protein 2/3 (Arp2/3) complex, Rho-associated protein kinase 1 (ROCK), and myosin are important regulators of viscosity-induced ECM remodeling. In the context of viscosity-induced cell spreading, cells cultured on glass and collagen substrates exhibit markedly different responses to pharmacological treatments, indicating that microtubules, Rac1, and Arp2/3 play distinct roles in regulating cellular spreading depending on the substrate. In addition, our results demonstrate that high osmotic pressures override viscosity-induced cell spreading by suppressing membrane ruffling. Our results demonstrate viscosity as a regulator of ECM remodeling and cell spreading in a fibrillar microenvironment. We also reveal a complex interplay between viscosity and osmolarity. We anticipate that our research can pave the way for future investigations into the crucial roles played by viscosity in both physiological and pathological conditions.

Heparan sulphate binding controls in vivo half-life of the HpARI protein family

The parasitic nematode Heligmosomoides polygyrus bakeri secretes the HpARI family, which bind to IL-33, either suppressing (HpARI1 and HpARI2) or enhancing (HpARI3) responses to the cytokine. We previously showed that HpARI2 also bound to DNA via its first complement control protein (CCP1) domain. Here, we find that HpARI1 can also bind DNA, while HpARI3 cannot. Through the production of HpARI2/HpARI3 CCP1 domain-swapped chimeras, DNA-binding ability can be transferred, and correlates with in vivo half-life of administered proteins. We found that HpARI1 and HpARI2 (but not HpARI3) also binds to the extracellular matrix component heparan sulphate (HS), and structural modelling showed a basic charged patch in the CCP1 domain of HpARI1 and HpARI2 (but not HpARI3) which could facilitate these interactions. Finally, a mutant of HpARI2 was produced which lacked DNA and HS binding, and was also shown to have a short half-life in vivo. Therefore, we propose that during infection the suppressive HpARI1 and HpARI2 proteins have long-lasting effects at the site of deposition due to DNA and/or extracellular matrix interactions, while HpARI3 has a shorter half-life due to a lack of these interactions.

Heparan sulphate binding controls in vivo half-life of the HpARI protein family.

The parasitic nematode Heligmosomoides polygyrus bakeri secretes the HpARI family, which bind to IL-33, either suppressing (HpARI1 and HpARI2) or enhancing (HpARI3) responses to the cytokine. We previously showed that HpARI2 also bound to DNA via its first complement control protein (CCP1) domain. Here, we find that HpARI1 can also bind DNA, while HpARI3 cannot. Through the production of HpARI2/HpARI3 CCP1 domain-swapped chimeras, DNA-binding ability can be transferred, and correlates with in vivo half-life of administered proteins. We found that HpARI1 and HpARI2 (but not HpARI3) also binds to the extracellular matrix component heparan sulphate (HS), and structural modelling showed a basic charged patch in the CCP1 domain of HpARI1 and HpARI2 (but not HpARI3) which could facilitate these interactions. Finally, a mutant of HpARI2 was produced which lacked DNA and HS binding, and was also shown to have a short half-life in vivo. Therefore, we propose that during infection the suppressive HpARI1 and HpARI2 proteins have long-lasting effects at the site of deposition due to DNA and/or extracellular matrix interactions, while HpARI3 has a shorter half-life due to a lack of these interactions.

Equilibria of large random Lotka-Volterra systems with vanishing species: a mathematical approach.

Ecosystems with a large number of species are often modelled as Lotka-Volterra dynamical systems built around a large interaction matrix with random part. Under some known conditions, a global equilibrium exists and is unique. In this article, we rigorously study its statistical properties in the large dimensional regime. Such an equilibrium vector is known to be the solution of a so-called Linear Complementarity Problem. We describe its statistical properties by designing an Approximate Message Passing (AMP) algorithm, a technique that has recently aroused an intense research effort in the fields of statistical physics, machine learning, or communication theory. Interaction matrices based on the Gaussian Orthogonal Ensemble, or following a Wishart distribution are considered. Beyond these models, the AMP approach developed in this article has the potential to describe the statistical properties of equilibria associated to more involved interaction matrix models.

Influence of carboxyl functionalized MWCNT loading on the thermal stability and long-term water uptake behavior in tri-layered jute FRCs

Investigations on the influence of carboxyl functionalized MWCNTs on epoxy composites solely reinforced by jute fiber are very scarce. Therefore, an attempt has been made to analyze the long-term moisture absorption behavior and thermal stability at the high-temperature range (30 °C-1200 °C) in jute FRC filled with varying amounts of functionalized MWCNTs (wt. %). Jute fibers derived from needle-punched jute mats were chemically pre-treated and were studied using Fourier Transform Infrared Spectroscopy (FT-IR). The MWCNTs were ultrasonicated to ensure uniform dispersion in the epoxy matrix. Scanning Electron Microscopy (SEM) was performed to observe the fiber, matrix, and filler interactions. As the composites were fabricated using the hand layup technique, air bubbles got entrapped into the specimens for which the void content was also reported. At a substantial saturation state (weight change <5 mg), the composite with 1 % MWCNT absorbed the most water. However, at higher CNT loadings, MWCNT agglomeration stopped water uptake. These results suggest that careful adjustment of MWCNT loading is necessary to balance hydrophilicity and porosity, thereby fine-tuning the water absorption of jute FRC. Thermogravimetric analysis (TGA) has been used in the study to assess the thermal behavior of the composites, indicating that adding MWCNTs at about 1 wt. % CNT loading can increase the thermal stability of jute fiber composites. An elevated concentration of CNTs facilitates agglomeration, impeding moisture absorption, whereas the incorporation of 1 % CNTs improves thermal stability. Consequently, a CNT concentration of 1.5 % is recommended.

Ensemble Monte Carlo transport studies of zinc-blende cuprous halides

We present a comprehensive theoretical analysis of intrinsic high-field transport in cuprous halides: CuCl, CuBr, and CuI. Ensemble Monte Carlo transport simulations were performed based on analytical approximations of the multi-valley and three-band electronic structure model. The deformation potentials, extracted from carrier–phonon interaction matrix elements calculated via the Wannier function approach, were employed to determine scattering rates. Our detailed analysis uncovers intriguing transport characteristics based on the complex valence band structures, resulting from spin–orbit coupling and band inversion. Remarkably, the hole mobility in CuI was exceptionally high, reaching up to 193 cm2/V s, while CuCl exhibited unusual temperature dependencies in hole transport. Additionally, the electron mobility in CuI was found to be 254 cm2/V s, indicating a minimal disparity between carrier mobilities, which is advantageous for optoelectronic applications.

Risk assessment through feature, event, and process for repurposing suspended oil and gas wells for geothermal purposes

Many countries have set the goal of net zero carbon emission and are diverting their energy source towards renewables. In that respect, geothermal energy is a continuous renewable energy source that is not affected by any metrological conditions. However, geothermal energy is not used to its full potential, and at present, less than 1 % of renewable energy is produced by geothermal sources. One of the biggest reasons that hinder its adoption is the cost of drilling and completion associated with the geothermal well, which almost takes 50 % of the project budget. Therefore, it is important that, where possible (with conducive geothermal conditions), conventional oil and gas wells that are old or temporarily suspended should be retrofitted into geothermal wells. In this way, the initial cost of the geothermal project can be reduced, which is mainly due to the drilling operations. However, before repurposing old retired wells, conducting a proper risk assessment is important to avoid any well integrity issues in the long run. Therefore, this paper presents a concept of accessing the risk using Feature, Event, and Process (FEP) that have been integrated with the interaction matrix, incident potential matrix (IPM), and cause-effect plot diagram. This risk assessment technique identifies the well components that might be susceptible to failure, and remedial work should be conducted on such elements. However, geothermal wells have no specific FEPs; hence, the FEPs from CCS wells have been used, which have their limitation when used for geothermal systems. Nonetheless, to show the feasibility of this approach in assessing the risk, two case studies of the fictitious tubingless geothermal well are presented in this paper.

Block-Correlated Coupled Cluster Theory Based on the Generalized Valence Bond Reference for Singlet-Triplet Energy Gaps of Strongly Correlated Systems.

A block-correlated coupled cluster (BCCC) method based on the triplet generalized valence bond (GVB) wave function (GVB-BCCC) has been implemented for the first time. By introducing several techniques, we have developed a practical and efficient GVB-BCCC code. The GVB-BCCC3 method (with up to three-pair correlation) can be used to deal with strongly correlated (SC) systems with triplet or singlet ground states, allowing singlet-triplet (S-T) energy gaps in the active space of SC systems computationally available. For selected SC systems, our calculations show that GVB-BCCC3 can always provide correct ground-state spin multiplicity as the complete active space configuration interaction (CASCI) or density matrix renormalization group (DMRG). Furthermore, we found that the S-T energy gaps from GVB-BCCC3 are quite consistent with CASCI or DMRG results. This work demonstrates that GVB-BCCC3 is a promising theoretical tool for describing S-T energy gaps within the active space of SC systems with large active spaces.