Core Structure Research Articles

Analysis of concrete architecture of Bitcoin Core

Bitcoin Core serves as the foundational software responsible for verifying and validating all transactions and blocks within the Bitcoin blockchain, hence upholding the security and integrity of the whole Bitcoin network. This study extensively examines the internal mechanisms, structure, and conceptual framework of Bitcoin Core. This study aims to conduct a comprehensive analysis of the Bitcoin Core architecture, with a focus on evaluating its capacity to fulfill the rigorous demands of a decentralized Bitcoin network. This study not only provides a comprehensive understanding of the essential elements that drive the Bitcoin network, but it also explores the numerous factors that have a substantial impact on the operational availability of Bitcoin nodes. All of these factors are essential for ensuring the efficient operation of the Bitcoin network, encompassing the physical environment, architectural designs of nodes, and maintenance requirements. This study provides a comprehensive analysis of the underlying mechanisms of Bitcoin, shedding light on its inherent robustness and the factors that contribute to its consistent performance within the ever-changing landscape of digital currencies. The objective of this endeavor is to furnish a detailed exposition of the mechanics of Bitcoin, so enhancing its prevalence and familiarity among individuals.

Evaluation of structure, processes, and results of hospital epidemiology cores in the metropolitan region of Goiânia (GO), Brazil

Introduction: The expansion of the scope of Epidemiological Surveillance actions to the hospital level began with the legal prerogative of Ordinance No. 2,529, dated November 2004. Objective: To describe the Hospital Epidemiology Cores (HECs) of hospitals in the Metropolitan Region of Goiânia, Goiás, Brazil, in terms of resources, work processes, and outcomes. Method: This is a cross-sectional study. The theoretical framework for evaluating the HECs used in this research will be based on Avedis Donabedian's model, which relies on the dimensions of structure, process, and outcome. Five hospitals with implemented Hospital Epidemiology Cores participated in the study. Results: The most frequent age group of participants was 20 to 59 years (95.0%), and the majority of the sample was female (90%). Regarding the active search for Epidemiologically Important Events (EIEs) by the HECs, all five units operationalize this work process. Conclusion: The study demonstrated that, from the perspective of physical structure and material and equipment, the cores showed good conditions. All HECs actively search for EIEs in priority areas of the hospital.

Preparation of sodium alginate encapsulated anionic polyacrylamide microcapsules with delayed thickening performance

Polyacrylamide (PAM) is a polymer compound that is widely used in oil extraction, wastewater treatment, food processing and other fields. As a typical polymer flooding agent, PAM has received much attention in the field of oil extraction due to its unique of viscoelastic properties. However, polymer flooding faces several challenges in oil reservoirs, including high injection pressure, high shear loss and crossflow. In an effort to overcome this challenge, we designed a method of coating Ca2+ cross-linked sodium alginate onto the core structure of polyacrylamide, providing shear resistance and sustained release performance for the polymer. The important role of the shell material was indirectly demonstrated by measuring its apparent viscosity using digital rotary viscometer. Moreover, the swelling behavior of microcapsules in water was observed using an optical microscope. The protective shell made the slow release of anionic PAM into water under stirring at 500 rpm, maintaining the viscosity of the fluid below 10 mPa·s within 2 h, and the viscosity increased from 1.8 mPa·s to 30 mPa·s after 35 h. In addition, this work revealed the importance of effective encapsulation by emulsification/external gelation method and a facile shell modification by the layer-by-layer self-assembly method.

Asymmetry of Submesoscale Instabilities in Anticyclonic and Cyclonic Eddies

AbstractThe upper‐ocean relative vorticity has been found to be cyclonically skewed, but altimetry observations indicate that long‐lifespan mesoscale eddies tend to be anticyclonic. We are thus interested in whether cyclonic or anticyclonic eddies are more unstable under similar circumstances. Here we use submesoscale‐resolving simulations of idealized mesoscale eddies, incorporating theoretical analyses, to investigate asymmetries of submesoscale instabilities within the anticyclones and cyclones. It is found that submesoscale filaments initiate at regions with the largest horizontal buoyancy gradients for both anticyclones and cyclones, but these filaments subsequently rotate outward in anticyclones while inward in cyclones. Hence submesoscales are more vigorous at anticyclone peripheries and the cyclone center. Such differing distributions and evolutions of submesoscale processes are primarily caused by changes in the background stratification associated with the decaying of mesoscale eddies. The active submesoscales near the cyclone center eventually distort its core structure radically, whereas the anticyclone remains largely unaffected.

Weak‐Chelation Assisted Regioselective Indole C(4)‐Alkynylation via Six‐Membered Cobaltacycle Intermediate

AbstractHerein a regioselective indole C4‐alkynylation has been uncovered utilizing an earth‐abundant cobalt(III)‐catalyst. For this process, (bromoethynyl)benzene was used as an alkynylating agent. Also, after screening various amide‐protected chelating groups we found dimethyl‐amide is optimal for the in‐situ generation of cobaltacycle intermediate. The six‐membered cobaltacycle intermediate has been detected through high‐resolution mass spectrometry HRMS, which is a key intermediate for this conversion. Further, mechanistic studies were performed such as KIE experiments, and reactions with radical scavengers, and based on the results a plausible mechanism has been proposed. Moreover, to show the application of this methodology, the product has been oxidized to diketone, monoketone, alkene, alkane and further derivatized to a tricycle indole derivative, which is a core structure of many natural products.

Synthesis of polysubstituted azepanes by dearomative ring expansion of nitroarenes.

The synthesis of functionalized nitrogen heterocycles is integral to discovering, manufacturing and evolving high-value materials. The availability of effective strategies for heterocycle synthesis often biases the frequency of specific ring systems over others in the core structures of bioactive leads. For example, while the six- and five-membered piperidine and pyrrolidine are widespread in medicinal chemistry libraries, the seven-membered azepane is essentially absent and this leaves open a substantial area of three-dimensional chemical space. Here we report a strategy to prepare complex azepanes from simple nitroarenes by photochemical dearomative ring expansion centred on the conversion of the nitro group into a singlet nitrene. This process is mediated by blue light, occurs at room temperature and transforms the six-membered benzenoid framework into a seven-membered ring system. A following hydrogenolysis provides the azepanes in just two steps. We have demonstrated the utility of the strategy with the synthesis of several azepane analogues of piperidine drugs.

Innovation of Business Models in the Digital Era: A Case Study of the New Generation Digital Platform of the Information Network

Business model innovation in the digital age is an important exploration carried out by various industries to adapt to market demand, driven by the trend of digitization. This paper takes the new generation digital platform of the Information Network as a case study to deeply study its business model innovation practice and its position in the digital era business model innovation. By analyzing the development history, core structure, functions, and user and market impact of the platform, the unique value of the platform in business model innovation has been revealed. At the same time, a detailed analysis of the evolution of information network business models, core value chains, profit models, and competitive strategies comprehensively presents the diversity and innovation of information network digital platform business models. In practice, the impact of e-commerce, sharing economy, mobile payments, and financial technology on business model innovation was explored, highlighting the diversified paths of business innovation in the digital age. Finally, through in-depth analysis of innovative strategies such as customer value, data-driven decision-making, and multi-channel integration, insights are provided for future business model innovation in the digital age.

Investigation of the correlation between the substituent effect of ligands and the catalytic activity/magnetic properties in fine-tuned rare-earth complexes

Amine-bis(benzothiazole phenol) ligands, C1NNBiBTHP-H2 and CLNNBiBTHP-H2 ligands, were designed for yttrium complexes with analogous structures. A series of nitrophenolate (NP)-type of ligands possessing R substituents with variable electronic properties (R = NO2, Cl, H, CH3) on ortho and/or para position attached to the phenolate rings have been selected as secondary ligands for complexes syntheses. Ten novel yttrium complexes have been synthesized, [Y(C1NNBiBTHP)(NP)(MeOH)] (1–5) and [Y(CLNNBiBTHP)(NP)(MeOH)] (6–10) where the secondary ligand NP = 2,4-dinitrophenol(1 and 6), 2,5-dinitrophenol (2 and 7), 2-nitrophenol (3 and 8), 4-chloro-2-nitrophenol (4 and 9) and 4-methyl-2-nitrophenol (5 and 10), as well as the structures and catalytic properties for lactide (LA) polymerization were both studied. All the core structures and coordination geometries for complexes 1–10 were isostructural. All complexes were demonstrated to be active catalysts for LA polymerization, and the catalytic performance for these complexes was compared. The dysprosium analogues (11, 12 with C1NNBiBTHP-H2 and 13, 14 with CLNNBiBTHP-H2) also been synthesized and the magnetic properties of these compounds are fully studied. Comparing a series of nitrophenolate co-ligands in two different ligand systems, we presented the first example to study the correlation between electronic effect of the ligands and catalytic properties for mononuclear rare-earth complexes.

Highly stretchable conductor with elastomeric passivation sheath enabling applications in harsh conditions

The rapid development of robotics requires stretchable electrical conductors capable of large deformations and having high operational stability in terms of electrical and mechanical characteristics. Carbon nanotubes (CNT) have been considered as the primary component of stretchable conductors, and mechanically drawn CNT sheets have shown their functionality when combined with various elastomeric materials in the shape of yarns. Herein, an electrically passivated stretchable conductor with an elastomer sheath and a spandex–CNT coiled-yarn core structure is reported. Based on the proven performance of spandex–CNT coiled-yarn, the electrical insulation by the Ecoflex elastomer enhances its applicability in an actual situation without degrading the stretchable conductor functionality. The experimental results show a substantial working deformation range (up to 350%), high durability, and low resistance variation during repetitive stretch and release cycles. Additionally, its stability is confirmed over a wide temperature range (up to 150 °C) and even inside an acidic liquid environment where the elastomeric sheath protects the conducting core. The perfect cooperation between the Ecoflex sheath and spandex–CNT core opens the possibility of deploying this stretchable conductor technology under harsh conditions.

Lightweight honeycomb furniture panels with discreetly located strengthening blocks

Furniture manufacturers indicate they know the benefits of lightweight honeycomb panels but still expect their higher mechanical properties. This work presents a numerical and experimental approach to designing new tables manufactured of paper honeycomb panels with discreetly arranged reinforcing blocks in the core. The main goal was to determine whether the discrete arrangement of the blocks affects the strength and amount of energy absorbed by the newly designed tables and stiffness of honeycomb panels. Optimization reduced the weight of the panels by up to 30 %. At the same time, their linear elastic modulus was increased from 1579 MPa to 1771 MPa. After ten load cycles, tables with discrete reinforcements have a stiffness up 86.85–87.20 % of the stiffness of the reference table. After destructive tests up 89.96–91.16 %. Ultimately, the test results demonstrate the effectiveness of replacing wide slats with discreetly placed reinforcing blocks in the core structure.

Biopolymer hydrogel matrices for the stabilization and in-vitro delivery of anti-cancer polyoxometalate [CoW11O39(CpTi)]7−

In the present study, the polyoxometalate (POM), [CoW11O39(CpTi)]7−, known for its significant anti-cancer activity and relatively low toxicity compared to established organic drugs such as CP and 5FU, is investigated. However, it is acknowledged that POMs inherently exhibit toxicity to living cells due to the presence of heavy and toxic metal ions within their core structures and their limited selectivity toward biological targets. Consequently, a methodology to mitigate this toxicity is sought by encapsulating these POMs within hydrogel matrices, with the intention to facilitate slow, sustained release and enhanced target specificity. In this study, the hydrogel of the well-researched anti-cancer POM, K6H[CoW11O39(CpTi)] (hereafter abbreviated as CoW11CpTi), is synthesized through the electrostatic interaction of the positively charged carboxymethyl chitosan (CMC), carboxymethyl cellulose (CMCell), and gelatin, which serve as hydrogelators. Subsequent characterization of the resultant CMC-CoW11CpTi, CMCell-CoW11CpTi, and gelatin-CoW11CpTi gels is performed utilizing Fourier Transform Infrared Spectroscopy (FT-IR), Differential Scanning Calorimetry/Thermogravimetric Analysis (DSC/TGA), Electron Spin Resonance (ESR) Spectroscopy, Scanning Electron Microscopy (SEM), and Tgel analysis. Among these, the gelatin-CoW11CpTi gel demonstrates the highest stability, retaining its structural integrity for in excess of 10 days. In addition, cytotoxicity assays are conducted on an assortment of cell lines including NRK52e (Rattus norvegicus kidney cell line), MDA-MB-231 (human breast adenocarcinoma), and MCF-7 (human breast epithelial adenocarcinoma). It is observed that the release of POM from the hydrogel matrices under physiological pH conditions exhibits a slow and sustained profile. This study therefore offers a promising approach for the effective delivery of POMs in cancer therapy.

Mechanical Properties of Sandwiched Construction with Composite and Hybrid Core Structure

In the field of lighter substitute materials, sandwich plate models of composite and hybrid foam cores are used in this study. Three core structures: composite core structure and then the core is replaced by a structure of a closed and open repeating cellular pattern manufactured with 3D printing technology. It finally integrated both into one hybrid open-cell core filled with foam and employed the same device (WBW-100E) to conduct the three-point bending experiment. The test was conducted based on the international standard (ASTM-C 393-00) to perform the three-point bending investigation on the sandwich structure. Flexural test finding, with the hybrid polyurethane/polytropic acid (PUR/PLA) core, the ultimate bending load is increased by 127.7% compared to the open-cell structure core. In addition, the maximum deflection increased by 163.3%. The simulation results of three-point bending indicate that employing a hybrid combination of PUR-PLA led to an increase of 382.3%, and for PUR–TPU by 111.8%; however, the highest value recorded with PUR/PLA, which has the slightest stress error among the tests. Also, it is reported that when the volume fraction of reinforced aluminum particles is increased, the overall deformation becomes more sufficient, and the test accuracy improves; for example, rising from 0.5% to 3%, the midspan deflection of composite (foam-Al) is increased by 40.34%. There were noticeable improvements in mechanical properties in the 2.5% composite foam-Al.

Unveiling the effect of Ni on the formation and structure of Earth’s inner core

Ni is the second most abundant element in the Earth's core. Yet, its effects on the inner core's structure and formation process are usually disregarded because of its electronic and size similarity with Fe. Using ab initio molecular dynamics simulations, we find that the bcc phase can spontaneously crystallize in liquid Ni at temperatures above Fe's melting point at inner core pressures. The melting temperature of Ni is shown to be 700 to 800 K higher than that of Fe at 323 to 360 GPa. hcp, bcc, and liquid phase relations differ for Fe and Ni. Ni can be a bcc stabilizer for Fe at high temperatures and inner core pressures. A small amount of Ni can accelerate Fe's crystallization at core pressures. These results suggest that Ni may substantially impact the structure and formation process of the solid inner core.

Mode of carbon and energy metabolism shifts lipid composition in the thermoacidophile Acidianus.

The degree of cyclization, or ring index (RI), in archaeal glycerol dibiphytanyl glycerol tetraether (GDGT) lipids was long thought to reflect homeoviscous adaptation to temperature. However, more recent experiments show that other factors (e.g., pH, growth phase, and energy flux) can also affect membrane composition. The main objective of this study was to investigate the effect of carbon and energy metabolism on membrane cyclization. To do so, we cultivated Acidianus sp. DS80, a metabolically flexible and thermoacidophilic archaeon, on different electron donor, acceptor, and carbon source combinations (S0/Fe3+/CO2, H2/Fe3+/CO2, H2/S0/CO2, or H2/S0/glucose). We show that differences in energy and carbon metabolism can result in over a full unit of change in RI in the thermoacidophile Acidianus sp. DS80. The patterns in RI correlated with the normalized electron transfer rate between the electron donor and acceptor and did not always align with thermodynamic predictions of energy yield. In light of this, we discuss other factors that may affect the kinetics of cellular energy metabolism: electron transfer chain (ETC) efficiency, location of ETC reaction components (cytoplasmic vs. extracellular), and the physical state of electron donors and acceptors (gas vs. solid). Furthermore, the assimilation of a more reduced form of carbon during heterotrophy appears to decrease the demand for reducing equivalents during lipid biosynthesis, resulting in lower RI. Together, these results point to the fundamental role of the cellular energy state in dictating GDGT cyclization, with those cells experiencing greater energy limitation synthesizing more cyclized GDGTs.IMPORTANCESome archaea make unique membrane-spanning lipids with different numbers of five- or six-membered rings in the core structure, which modulate membrane fluidity and permeability. Changes in membrane core lipid composition reflect the fundamental adaptation strategies of archaea in response to stress, but multiple environmental and physiological factors may affect the needs for membrane fluidity and permeability. In this study, we tested how Acidianus sp. DS80 changed its core lipid composition when grown with different electron donor/acceptor pairs. We show that changes in energy and carbon metabolisms significantly affected the relative abundance of rings in the core lipids of DS80. These observations highlight the need to better constrain metabolic parameters, in addition to environmental factors, which may influence changes in membrane physiology in Archaea. Such consideration would be particularly important for studying archaeal lipids from habitats that experience frequent environmental fluctuations and/or where metabolically diverse archaea thrive.

Skeletal editing of pyridines through atom-pair swap from CN to CC.

Skeletal editing is a straightforward synthetic strategy for precise substitution or rearrangement of atoms in core ring structures of complex molecules; it enables quick diversification of compounds that is not possible by applying peripheral editing strategies. Previously reported skeletal editing of common arenes mainly relies on carbene- or nitrene-type insertion reactions or rearrangements. Although powerful, efficient and applicable to late-stage heteroarene core structure modification, these strategies cannot be used for skeletal editing of pyridines. Here we report the direct skeletal editing of pyridines through atom-pair swap from CN to CC to generate benzenes and naphthalenes in a modular fashion. Specifically, we use sequential dearomatization, cycloaddition and rearomatizing retrocycloaddition reactions in a one-pot sequence to transform the parent pyridines into benzenes and naphthalenes bearing diversified substituents at specific sites, as defined by the cycloaddition reaction components. Applications to late-stage skeletal diversification of pyridine cores in several drugs are demonstrated.

Insights into the structure-activity relationship of pyrimidine-sulfonamide analogues for targeting BRAF V600E protein

B-rapidly accelerated fibrosarcoma (BRAF) V600E plays a crucial role in the progression of cutaneous melanoma. Core structures of BRAF V600E inhibitors are based on pyrimidine-sulfonamide scaffolds. Exploring the QSAR of these structures can improve our understanding of BRAF V600E inhibitor drug design. This study utilized machine learning-based QSAR to elucidate chemical substructures of pyrimidine-sulfonamide analogues that correlated to the BRAF V600E inhibitory activity. The findings indicate that the support vector regression (SVR) combined with 15 fingerprints achieved the highest statistical performances in terms of goodness-of-fit, robustness, and predictability. Nine key fingerprints from pyrimidine-sulfonamide analogues were identified to exert the BRAF V600E inhibitory activity. These key fingerprints were validated using network-based activity cliff landscape and molecular docking. Together, the developed algorithm can serve as a screening tool for designing BRAF V600E inhibitors. To further utilize this model, we deployed our developed algorithm at https://qsarlabs.com/#braf.

Recent Advances in Pyrimidine-Based Drugs.

Pyrimidines have become an increasingly important core structure in many drug molecules over the past 60 years. This article surveys recent areas in which pyrimidines have had a major impact in drug discovery therapeutics, including anti-infectives, anticancer, immunology, immuno-oncology, neurological disorders, chronic pain, and diabetes mellitus. The article presents the synthesis of the medicinal agents and highlights the role of the biological target with respect to the disease model. Additionally, the biological potency, ADME properties and pharmacokinetics/pharmacodynamics (if available) are discussed. This survey attempts to demonstrate the versatility of pyrimidine-based drugs, not only for their potency and affinity but also for the improved medicinal chemistry properties of pyrimidine as a bioisostere for phenyl and other aromatic π systems. It is hoped that this article will provide insight to researchers considering the pyrimidine scaffold as a chemotype in future drug candidates in order to counteract medical conditions previously deemed untreatable.

An inverse analysis procedure for characterizing the homogeneous skull model used for predicting blast-induced brain response

Based upon the homogeneous skull model, the skull/brain assembly can be simplified as a homogeneous-shell (HMS)/core structure, in which the exterior shell and interior core represent the skull and brain, respectively. From the blast responses of the spherical shell/core structures calculated via finite element modeling, it is found that the existing homogeneous skull model developed by the well-accepted approach based upon three-point bending tests cannot properly describe the blast response of the skull, modeled as a three-layered sandwich (TLS) shell in the present work, e.g. the average error in the calculated core (brain) pressure is up to ∼30%. Moreover, an innovative approach based upon inverse analysis procedure is then proposed to develop a modified homogeneous skull model, which can give a proper description of the blast response of the skull (a TLS shell), e.g. the average error in the calculated core (brain) pressure is reduced to ∼7%. It is concluded that the well-accepted three-point bending approach cannot develop an effective HMS skull model for studying the blast response of the skull/brain assembly, upon which the model parameter will be overestimated by ∼60%; instead, the innovative approach based upon inverse analysis procedure should be adopted.

TPGS-mediated Transethosomes Enhance Transdermal Administration of Curcumin via Effects on Deformability and Stability.

Adding a suitable surfactant can enhance the transdermal permeability of transethosomes while also leveraging its functionality as a functional material. In this study, transethosomes were prepared using D-α-tocopherol acid polyethylene glycol succinate (TPGS) as edge activators for transdermal delivery of curcumin (Cur). The TPGS-mediated curcumin-loaded transethosomes (Cur@TES) were prepared and formulated optimally, and the optimized formulations were characterized for their morphology, particle size, entrapment efficiency (EE) and drug loading (DL). The stability and deformability of Cur@TES were investigated, while the transdermal delivery of Cur@TES was investigated through in vitro transdermal assays and fluorescence imaging. A mouse ear swelling model was performed to determine the anti-inflammatory effect of Cur@TES. Cur@TES appeared round or elliptical in shape. The particle size, EE and DL for the optimized formulation were observed as 131.2 ± 7.2 nm, 97.68 ± 2.26%, and 6.58 ± 0.62%, respectively. X-ray diffraction analysis confirmed the formation of disordered structures in the inner core of the vesicles. Moreover, Cur@TES system demonstrated better stability and deformability compared to the curcumin-loaded ethosomes (Cur@ES). In-vitro transdermal experiments demonstrated that Cur@TES significantly increased the amount of drug retained in the skin (P＜0.05). Fluorescence imaging confirmed that the skin distribution were distinctly enhanced with the delivery by TPGS mediated transethosomes. In addition, Cur@TES showed a significant inhibitory effect on Inflammatory swelling in the mouse ear-swelling model. TPGS-mediated transethosomes exhibit significant transdermal advantages and enhanced anti-inflammatory effects, providing a new perspective for the transdermal delivery of curcumin.

Density Functional Theory Simulation of Dithienothiophen[3,2-b]-pyrrolobenzothiadiazole-Based Organic Solar Cells

We have simulated the effect of changing the end groups in BTP core with five organic units of 1,3-Indandione (IN), 2-thioxothiazolidin-4-one (Rhodanine), propanedinitrile (Malononitrile), (2-(6-oxo-5,6-dihydro-4H-cyclopenta[c]thiophen-4-ylidene)malononitrile) (CPTCN) and 2-(3-oxo-2,3-dihydroinden-1-ylidene (IC), and two halogenated units of (4F) IC and (4Cl) IC on the optical and photovoltaic properties of the BTP DA’D core molecular unit. Thus modified, seven molecular structures are considered and their optical properties, including HOMO and LUMO energies and absorption spectra are simulated in this paper. On the basis of HOMO and LUMO energies, it is found that two of the seven molecules, BTP-IN and BTP-Rhodanine, can act as donors and the other four, BTP-(4F) IC, BTP-(4Cl) IC, BTP-CPTCN and BTP-IC, as acceptors in designing bulk heterojunction (BHJ) organic solar cells (OSCs). Using these combinations of donors and acceptors in the active layer, eight BHJ OSCs, such as BTP-IN: BTP-(4F) IC, BTP-IN: BTP-(4Cl) IC, BTP-IN: BTP-CPTCN, BTP-IN: BTP-IC, BTP-Rhodanine: BTP-(4F) IC, BTP-Rhodanine: BTP-(4Cl) IC, BTP-Rhodanine: BTP-CPTCN and BTP-Rhodanine: BTP-IC, are designed, and their photovoltaic performance is simulated. The photovoltaic parameters Jsc, Voc and FF for all eight BHJ OSCs and their power conversion efficiency (PCE) are simulated. It is found that the BHJ OSC of the BTP-IN: BTP-CPTCN donor–acceptor blend gives the highest PCE (14.73%) and that of BTP-Rhodanine: BTP-(4F) IC gives the lowest PCE (12.07%). These results offer promising prospects for the fabrication of high-efficiency BHJ OSCs with the blend of both donor and acceptor based on the same core structure.