Core Position Research Articles

The initial stage of the coalescence of a compound drop in an impact regime

The evolution of the regular fine structure of the colored matter distribution produced, when a freely falling multifluid drop spreads in deep water, is for the first time traced using the techniques of engineering photo and video recording. The flow pattern is studied in the initial stage of the formation of a cavity and a crown during the coalescence of a compound drop, whose core is a drop of alizarin ink solution coated with an oil shell. The distributions of the colored fluid at the cavity bottom and the crown walls include streaky structures, whose formation can be due to the processes of the available potential surface energy (APSE) conversion occurring when the contact surfaces of the merging fluids are eliminated. In the experiments the height of the falling drop was varied. The core position in the compound drop was not checked but was determined by separation conditions. The ink core disintegration into fibers was observable in all the experiments. The areas of the cavity and crown surfaces covered by the colored fluid reached maximum at the central position of the core.

In Silico Design, Chemical Synthesis, Biophysical and in Vitro Evaluation for the Identification of 1-Ethyl-1H-Pyrazolo[3,4-b]Pyridine-Based BRD9 Binders.

In this work, we report the identification of novel bromodomain-containing protein 9 (BRD9) binders through a virtual screening based on our developed 3D structure-based pharmacophore model. The in silico workflow here described led to the identification of a promising initial hit (1) featuring the 1-ethyl-1H-pyrazolo[3,4-b]pyridine motif which represented an unexplored chemotype for the development of a new class of BRD9 ligands. The encouraging biophysical results achieved for compound 1 prompted us to explore further tailored structural modification around the C-4 and C-6 positions of the central core. Hence, the design and synthesis of a set of 19 derivatives (2-20) were performed to extensively investigate the chemical space of BRD9 binding site. Among them, four compounds (5, 11, 12, and 19) stood out in biophysical assays as new valuable BRD9 ligands featuring IC50 values in the low-micromolar range. Noteworthy, a promising antiproliferative activity was detected in vitro for compound 5 on HeLa and A375 cancer cell line. The successful combination and application of in silico tools, chemical synthesis, and biological assays allowed to identify novel BRD9 binders and to expand the arsenal of promising chemical entities amenable to the recognition of this important epigenetic target.

The Effect of Molecular Structure on the Properties of Fluorene Derivatives for OLED Applications.

A new family of symmetrical fluorene derivatives with different types of substituents attached to the C-2 and C-7 positions of the fluorene core synthesized by the Sonogashira coupling reactions is reported. The electronic structures and the properties of the compounds investigated by means of photoelectron emission spectroscopy, UV-Vis absorption and photoluminescent spectroscopy as well as by DFT and TD-DFT theoretical calculations are discussed. It is shown that the nature of substituents influences the π-conjugation of the molecules. No intermolecular charge transfer within the investigated wavelength range is observed. The applicability of the synthesized compounds in organic light-emitting diodes (OLEDs) based on exciplex emission is demonstrated. The advanced co-deposition technique with the tuned OLED architecture was applied and resulted in improved OLED parameters.

Knowledge source switching under state interventions of latecomer regions: A case study of Shenzhen

This paper aims to unpack the process and analyze the mechanisms of knowledge source switching in latecomer regions that have evolved from peripheral to core positions. Drawing on four decades of matched patent-company data from Shenzhen, we classify patents into various knowledge classifications and calculate their percentage changes to observe the dynamics of knowledge source switching. Furthermore, we employ Difference-in-Differences (DiD) estimation to examine the causal effects of state interventions on this dynamic. The findings indicate that Shenzhen's knowledge sources have switched from multinational corporations (MNCs) and foreign subsidiaries to global inventors. Notably, state interventions exhibit a significant positive causal effect on this dynamic, particularly following the implementation of independent innovation policies. These findings contribute to the cross-fertilization of regional innovation studies and the Global Production Networks (GPN) approach, highlight the critical role of the state in ensuring the right and dynamic mode of global knowledge sourcing and offer implications for local innovation policies in latecomer regions.

Enhanced red UC emission of Er3+ ions by constructing multi-heterojunction core-shell nanoparticles

The construction of core-shell structures with multiple heterojunctions facilitates ion energy transfer and minimizes surface quenching effects, which are essential for enhancing and regulating the upconversion emission of materials. In this study, we effectively regulated the spatial distribution of Yb3+ and Er3+ ions in multilayered heterogeneous core-shell structures to significantly enhance the red upconversion emission of Er3+ ions. Specifically, the red emission intensity of the NaErF4@NaYbF4: 2 %Er3+@NaYF4 core-shell nanoparticles was enhanced nearly 24.4-fold compared to that of NaErF4 nanoparticles. This enhancement results from a bidirectional energy transfer process. Moreover, when we swapped the positions of the NaErF4 core and the NaYbF4: 2 %Er3+ shell and introduced NaYF4 inert isolation layer and Yb3+ ions, the red emission intensity of the NaYbF4:2 %Er3+@NaYF4:20 %Yb3+@NaErF4@ NaYF4 multilayer core-shell structure increased significantly by nearly 254.3-fold compared to NaErF4 nanoparticles. The remarkable enhancement of the red emission of Er3+ ions is primarily attributed to a well-organized bidirectional energy transfer process between the heavily doped core and shell Er3+-Yb3+ ion pairs. The energy transfer behavior of these multi-heterojunction core-shell nanoparticles was studied based on their spectral characteristics. The multilayer heterogeneous core-shell nanoparticles exhibited colorful emissions under different excitation conditions, highlighting their potential for biomedical applications and colorful anti-counterfeiting.

Theoretical Analysis of Viscoelastic Friction System Characteristics of Robotic Arm Brake Based on Fractional Differential Theory

In engineering practice, the nonlinear vibration effect can easily lead to chaos in the system, which will not only reduce the performance of the system but also lead to premature fatigue of components, control failure, and increased safety risks. In view of the core position of the robotic arm in modern industry, this study relies on the robotic arm brake system to explore the theoretical basis of integrated viscoelastic materials as a vibration isolation layer. By analyzing the dynamic characteristics of the friction braking system with fractional differential terms, it aims to provide a new perspective for understanding and controlling the chaotic phenomena of a class of nonlinear friction systems. Firstly, we construct a model of a friction system and analyze its dynamic characteristics in detail. The self-excited vibration of the system under disturbance is studied. The relationship between amplitude and frequency is calculated by a nonlinear approximate analytical algorithm, and the accuracy of this relationship is verified by a numerical algorithm. Then, we compare the differences between non-fractional systems and fractional systems. It is found that with the increase in the fractional order term, the vibration amplitude of the system decreases significantly, which helps to reduce the nonlinear characteristics generated by the friction system and narrow the range of unstable solutions. Secondly, we also study the influence of parameter coefficients on the amplitude–frequency characteristics and analyze the local static bifurcation characteristics through singularity theory. Finally, we study the dynamic bifurcation behavior under different parameter perturbations and find that the change in system parameters will lead to the alternation of periodic motion and chaotic motion.

Non-Aristotelian Elements in Carl Menger's Methodology

Abstract According to the dominant interpretation, Carl Menger, the founder of the Austrian school, was an Aristotelian methodologist of social science. As this article attempts to demonstrate, this influence was not decisive in shaping Menger's methodology. In fact, Menger shared several core positions with modern thinkers. Such non-Aristotelian threads in Menger tackled in the article encompass his views on essentialism and realism, a priori knowledge, the classification of sciences, and scientific value-freedom, as well as methods of historical inquiry. As is shown, while unattachable to any specific philosophical school, those five elements constitute a fairly consistent, non-Aristotelian account of economic methodology.

Baicalin Ameliorates Depression-like Behaviors via Inhibiting Neuroinflammation and Apoptosis in Mice

Depression is a common neuropsychiatric disease which brings an increasing burden to all countries globally. Baicalin, a flavonoid extracted from the dried roots of Scutellaria, has been reported to exert anti-inflammatory, antioxidant, and neuroprotective effects in the treatment of depression. However, the potential biological mechanisms underlying its antidepressant effect are still unclear. In the present study, we conducted extensive research on the potential mechanisms of baicalin’s antidepressant effect using the methods of network pharmacology, including overlapped terms-based analysis, protein–protein interaction (PPI) network topology analysis, and enrichment analysis. Moreover, these results were further verified through molecular docking, weighted gene co-expression network analysis (WGCNA), differential gene expression analysis, and subsequent animal experiments. We identified forty-one genes as the targets of baicalin in the treatment of depression, among which AKT1, IL6, TP53, IL1B, and CASP3 have higher centrality in the more core position. Meanwhile, the roles of peripheral genes derived from direct potential targets were also observed. Our study suggested that biological processes, such as inflammatory reaction, apoptosis, and oxidative stress, may be involved in the therapeutic process of baicalin on depression. These mechanisms were validated at the level of structure, gene, protein, and signaling pathway in the present study. Taken together, these findings propose a new perspective on the potential mechanisms underlying baicalin’s antidepressant effect, and also provide a new basis and clarified perspective for its clinical application.

Copper(II)‐Amine Complex‐Mediated Intramolecular Coupling of Gallates: A Bioinspired Solution to the Atroposelective Synthesis of Ellagitannins.

Total syntheses of the C‐glucosidic ellagitannins (−)‐punicacortein A, (−)‐epipunicacortein A and (+)‐castalin were accomplished for the first time, and those of the glucopyranosic ellagitannins (+)‐tellimagrandin I and (+)‐pedunculagin were revisited. The atroposelective construction of their characteristic hexahydroxydiphenoyl (HHDP) and nonahydroxyterphenoyl (NHTP) units relied on the use of different cupric‐amine complexes under different reaction conditions to mediate the intramolecular dehydrogenative coupling of galloyl groups at different positions of glucose cores. In particular, the monodentate n‐butylamine and the bidentate (–)‐sparteine were found to be complementary in their capacity to promote the regio‐ and atroposelective coupling of galloyl groups on a 4C1‐glucopyranosic core into 2,3‐O‐(S)‐ and/or 4,6‐O‐(S)‐HHDP units. Furthermore, replacing (–)‐sparteine by its optical antipode not only counteracted the substrate‐controlled induction of atroposelectivity to forge a 4,6‐O‐(R)‐HHDP unit, but it also enabled a 4C1 to 1C4 ring flip of the glucopyranosic core and hence the formation of 2,4‐O‐(R)‐ and 3,6‐O‐(R)‐HHDP units, such as those featured in the glucopyranosic ellagitannins phyllanemblinin B and geraniin.

Copper(II)-Amine Complex-Mediated Intramolecular Coupling of Gallates: A Bioinspired Solution to the Atroposelective Synthesis of Ellagitannins.

Total syntheses of the C-glucosidic ellagitannins (-)-punicacortein A, (-)-epipunicacortein A and (+)-castalin were accomplished for the first time, and those of the glucopyranosic ellagitannins (+)-tellimagrandin I and (+)-pedunculagin were revisited. The atroposelective construction of their characteristic hexahydroxydiphenoyl (HHDP) and nonahydroxyterphenoyl (NHTP) units relied on the use of different cupric-amine complexes under different reaction conditions to mediate the intramolecular dehydrogenative coupling of galloyl groups at different positions of glucose cores. In particular, the monodentate n-butylamine and the bidentate (-)-sparteine were found to be complementary in their capacity to promote the regio- and atroposelective coupling of galloyl groups on a 4C1-glucopyranosic core into 2,3-O-(S)- and/or 4,6-O-(S)-HHDP units. Furthermore, replacing (-)-sparteine by its optical antipode not only counteracted the substrate-controlled induction of atroposelectivity to forge a 4,6-O-(R)-HHDP unit, but it also enabled a 4C1 to 1C4 ring flip of the glucopyranosic core and hence the formation of 2,4-O-(R)- and 3,6-O-(R)-HHDP units, such as those featured in the glucopyranosic ellagitannins phyllanemblinin B and geraniin.

Applied static analysis and specialization of cross-core syscalls for multi-core AUTOSAR OS

The development of static real-time control systems often follows a closed-world assumption, allowing extensive RTOS-aware whole-program optimization. For single-core systems, previous work could show the high potential of control-flow-aware static system-call tailoring. However, due to an exponential state explosion in the analysis phase, it cannot simply be extended to a multi-core setting, since the core’s relative timing to each other is undetermined. In this work, we present MultiSSE, a multi-core capable and RTOS-aware static whole-system optimization. First, MultiSSE analyzes the system by determining the relative positions of multiple cores only when necessary. For that, it exploits structural control flow and optionally timing information to handle each core separately as much as possible. Based on the analysis result, a synthesis applies lock elision and system-call optimization to generate specialized multi-core real-time systems for AUTOSAR OS. To enable a static prediction of the run-time reduction, we additionally provide cost models for the optimized cross-core system calls and evaluate the approach with synthetic benchmarks and a real-world quadrotor application. MultiSSE was able to optimize or even completely elide costly cross-core system calls and system objects leading to a reduction of up to 14% of a task’s execution time. In this extended version of a conference publication (Entrup et al. 2023), we provide an advanced description, new cost models, and an end-to-end measurement by developing a synthesis complementing the analysis.

NIR photoactivated electron intersystem crossing to evoke calcium-mediated lysosome-dependent cell death and immunotherapy

The efficacy of photodynamic therapy (PDT) highly depends on the photosensitizer (PS). How to rationally design PS with an efficient inter-system crossing (ISC) rate to enable the capacity for reactive oxygen species (ROS) production, remains a great challenge. Herein, we have successfully provided two isomers at two positions of the BODIPY core with a decoration of cyclometalated Ir(III) fragment to avoid the disadvantages of themselves as PS for PDT. With the theoretical and experimental investigations, the intact connection with BODIPY and Ir(III) fragment has been confirmed to facilitate the ISC process to produce ROS. PS could be accumulated in the lysosome, and excited with a near-infrared wavelength light (630 nm). Due to the severe ROS production upon irradiation, the lysosome membrane permeabilization (LMP) was activated. The calcium homeostasis has been subsequently disrupted with the release of the lysosomal contents, resulting in acidosis and calcium-mediated lysosome-dependent cell death (autophagy blockage and mitochondrial apoptosis). The photodynamic immunotherapy was also evoked with the disturbed calcium homeostasis, which has been demonstrated with the bilateral tumor models in vivo. This study not only provided a superior NIR photosensitizer but also presented an effective strategy to reduce the energy gap via electron intersystem crossing to boost photodynamic immunotherapy.

Synergism of endophytic microbiota and plants promotes the removal of polycyclic aromatic hydrocarbons from the Alfalfa rhizosphere

Endophytic bacteria can promote plant growth and accelerate pollutant degradation. However, it is unclear whether endophytic consortia (Consortium_E) can stabilize colonisation and degradation. We inoculated Consortium_E into the rhizosphere to enhance endophytic bacteria survival and promote pollutant degradation. Rhizosphere-inoculated Consortium_E enhanced polycyclic aromatic hydrocarbon (PAH) degradation rates by 11.5–13.1 % compared with sole bioaugmentation and plant treatments. Stable-isotope-probing (SIP) showed that the rhizosphere-inoculated Consortium_E had the largest number of degraders (8 amplicon sequence variants). Furthermore, only microbes from Consortium_E were identified among the degraders in bioaugmentation treatments, indicating that directly participated in phenanthrene metabolism. Interestingly, Consortium_E reshaped the community structure of degraders without significantly altering the rhizosphere community structure, and strengthened the core position of degraders in the network, facilitating close interactions between degraders and non-degraders in the rhizosphere, which were crucial for ensuring stable functionality. The synergistic effect between plants and Consortium_E significantly enhanced the upregulation of aromatic hydrocarbon degradation and auxiliary degradation pathways in the rhizosphere. These pathways showed a non-significant increasing trend in the uninoculated rhizosphere compared with the control, indicating that Consortium_E primarily promotes rhizosphere effects. Our results explore the Consortium_E bioaugmentation mechanism, providing a theoretical basis for the ecological restoration of contaminated soils.

Anion-binding-induced selective aggregation and self-degradation: Influence of positional isomerism on the anion selectivity and mode of binding of an imine-based receptor

Imine based positional isomers (8E)-N-(4-((E)-(perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L and (10E)-N-(3-(E-Perfluorophenylimino)methyl)benzylidene)-2,3,4,5,6-pentafluorobenzenamine, L1 have been designed, and synthesized by functionalizing two electron deficient aromatic moieties at the para–para’/ortho-ortho’ positions in the phenyl core of the L and L1 respectively. The responses of L and L1 towards various anionic species are examined. The positional isomers L and L1 differs not only by showing distinguishable color change upon addition of anions but also differentiates themselves by the way of self-assembling together upon binding with cyanide anion. The naked-eye colorimetric experiments, UV–Vis, Nuclear Magnetic Resonance, and Infra-Red spectroscopic analyses reveal that the isomer L binds fluoride anion through 2:1 stoichiometry ratio. Unlike fluoride complex, the isomer L form aggregates while binding with cyanide ion. On the other hand, isomer L1 does not show any instant color change upon additions of any anion. Interestingly, after thirty minutes, only the color of the cyanide complex is turned into dark brown. While analyzing the spectroscopic results of cyanide complex of L1, it is found that the cyanide complex begins to decompose and finally it is completely decomposed within 30 min. This unprecedented phenomenon about the colorimetric sensing of cyanide and destruction of cyanide complex with respect to time has not been reported in the literature yet. To the best of our knowledge this is the first example of study of sensing controlling the selectivity, mode of binding, self-aggregating and degradation properties of anionic complexes under the influence of positional isomeric effects. This present investigation provides simple and effective strategy to construct the sensor molecules with tunable binding properties in terms of easy to prepare as well as easy to use as a colorimetric sensor._____________________________________________________________________________________________________

Statistical sampling method to verify the homogeneity of full-scale cement-solidified radioactive waste

Homogeneity is an important factor for ensuring the structural stability of solidified radioactive waste, and the most effective approach for assessing its homogeneity is by performing compressive strength measurements using the minimum amount of coring specimens. The efficiency of detecting inhomogeneous waste is affected by the coring position and number of coring positions. However, no guidelines exist for coring solidified waste for compressive-strength tests. Therefore, this study compared uniform, random, and quasi-Monte Carlo sampling methods to determine the most effective core position. Further, the effects of different sampling amounts on the detection rate of inhomogeneous solidified waste were observed, and the detection rate of the inhomogeneous waste was obtained by modeling the coring procedure of solidified radioactive waste using MATLAB. Thus, a sampling method and a method for increasing the specimen amount, both of which can efficiently detect inhomogeneous waste during compressive strength tests, were presented in this paper. The results of this study can be applied as background data for developing homogeneity assessment guidelines for solidified radioactive waste.

Islamist Government in Malaysia under PAS: Ideology, Policies, and Competition

ABSTRACT Dominant approaches to understanding Islamist politics tend to assume a uniform polity. Most notably, inclusion–moderation hypotheses presume Islamist parties are simply in or out: that the lure of office persuades radical Islamist groups to moderate their behaviour and ideologies to participate in elections. We suggest a different dynamic, in which an Islamist party adapts its mien and messaging to appeal simultaneously to heterogeneous audiences, without compromising its core positions. We find an exemplary case in Malaysia, where Parti Islam Se-Malaysia (Pan-Malaysian Islamic Party, PAS) contests both nationally and at the state level. At the federal level, PAS seeks support within a multi-ethnic, multi-religious polity, working in coalition with either secular, noncommunal parties, for whom an adamantly Islamist stance would be verboten, or Malay-ethnonationalist parties, for whom Islam is salient, but secondary. Meanwhile, PAS competes subnationally in its northeastern stronghold, where its confirmed Islamism confers strong advantage – but also in other states, with different approaches. Yet, across these stages, PAS sustains its underlying ideological consistency, especially on fraught social issues. We explore the extent to which electoral participation amid differing incentives reveals more a moderating effect on Islamist-party behaviour and ideology, or a capacity for strategic posturing.

Identity positioning of experienced school principals when facing critical incidents

The study focused on experienced school principals' identity positions when facing critical incidents that arise over the course of a school year with the aim of better understanding their identity positioning. Ultimately, we intended results to inform on training proposals and school principals’ professional identity development. We used a dialogic framework and a longitudinal design to analyze the positioning processes that allowed four experienced school principals to solve the incidents they faced during their regular activity. Results confirm the dynamic nature of identity and suggest that the positive resolution of critical incidents involved interventions from main positions (core positions, promotor positions, and meta-positions) coalitions with prominent secondary positions, and creation of new positions. Such results indicate to what extent dialogue helped principals deal consciously and strategically with the incidents that configure their professional practice and ultimately contribute to the construction of their identities.

Rational Design of Fluorophores Using MO Theory: Our Journey from BODIPYs to BOIMPYs

This short review demonstrates how MO-theoretical considerations can support the tailor-made design of new dye scaffolds, specifically the recently introduced BOIMPY class of fluorophores. Starting with historical and structural foundations, the influence of canonical streptocyanines on the electronic features of diarylmethenes and rhodamines is examined and the BODIPY scaffold is introduced as the primary structural inspiration for our work. The attachment of five-membered ring heterocycles at the meso position of the BODIPY core enables a relaxation into a co-planar and twofold chelating triarylmethene system. After introduction of two electron-withdrawing BF2 units, efficient rigidity is achieved since hindered rotation prevents non-radiative dissipation of energy via excited state relaxation. Hence, a lowered LUMO level allows the combination of a large red shift with high quantum efficiencies. The synthetic approach to BOIMPYs is straightforward and analogous to BODIPY syntheses starting from benzimidazole or tetrazole carbaldehydes. Cyclic voltammetric measurements prove that BOIMPYs are able to easily accept two electrons and might act as efficient photoredox catalysts.

Research and application of composite insulator overheat identification method based on improved case segmentation

Abstract How to quickly and accurately locate the heat of power components is one of the problems that need to be discussed frequently in the power field. At the same time, due to the diverse types of equipment in the power industry and the complex environment, if the heating position of the components cannot be located in time and further safety measures are taken, it will greatly affect whether the line can run stably. Based on infrared images, the device can be detected at a distance, and the problem can be found without interrupting its working state, which is more efficient in the process of equipment inspection. At present, some algorithms are based on infrared image research, but the positioning is not accurate, and some problems such as the temperature extracted by the algorithm and the temperature deviation between the actual parts caused by environmental factors, have not been a perfect solution. With regard to these problems, this paper presents a new method for overheating identification of composite insulators. First, the external profile of composite insulators is identified in infrared images through the YOLOV5 instance segmentation algorithm, and the rod core position of composite insulators is located based on this external profile. Then, the temperature matrix of the rod core position is obtained through the original heat matrix in infrared images. By comparing the temperature of the temperature matrix, we can determine whether the temperature is abnormal. In the actual production environment, the accuracy rate of the proposed method is 0.84, the error detection ratio is 0.2, and the total time of the algorithm is 216 ms. The results show that the proposed method has a good component positioning effect and can filter most of the temperature identification errors caused by environmental factors. It provides a new solution to solve the problem of temperature anomaly identification of overhead line power equipment in different scenarios.

A Photoredox Thiol-yne Reaction for the Synthesis of Vinyl Sulfide-Based Coumarins and its Effect on Fluorescence Properties.

Coumarins still remain one of the most widely explored fluorescent dyes, with a broad spectrum of applications spanning various fields, such as molecular imaging, bioorganic chemistry, materials chemistry, or medical sciences. Their fluorescence is strongly based on a push-pull mechanism involving an electron-donating group (EDG), mainly located at the C7 or C8 positions of the dye core. Unfortunately, up to now, these positions have been very limited to hydroxyl or amino groups. In this study, we present in detail the synthesis of the first series of coumarins bearing a vinyl sulfide as the EDG at the C7 position. These derivatives were prepared by thiol-yne reaction, promoted by ruthenium- or porphyrin-based photoredox catalysis, enabling rapid late-stage diversification. We also functionalized coumarins with short peptides, and BSA protein as a proof-of-concept study, in a single-step process. This strategy, capable of proceeding under aqueous conditions, overcomes the protection/deprotection steps usually required by traditional methods, which also use strong bases and organic solvents. Moreover, the photophysical properties such as absorption and emission of obtained coumarins (for 3-CF3, 3-benzothiazole, 6-8-difluoro derivatives), predominantly exhibited large Stokes shifts (up to 204 nm) and maintained intramolecular charge transfer (ICT) characteristics.