Analysis Of Complexes Research Articles

STATISTICAL INDICATORS OF THE CORRESPONDENCE OF THE LANGUAGE OF REGIONAL NEWSPAPERS IN KOSTROMA REGION TO ALL-RUSSIAN STANDARDS: A SYNTACTIC APPROACH

The paper is devoted to the analysis of complex sentences with subordinate clauses of condition, cause, goal, concession, consequence in regional newspapers of Kostroma Region in comparison with the data of similar studies conducted on the material of all-Russian periodicals. The grammar of the language, which is the backbone of the entire language system, is the most stable, standardised, which should be manifested at the syntactic level. The description of linguistic phenomena in the materials of regional periodicals in comparison with the all-Russia’s ones contributes to the forming of a general picture of the syntax of the modern Russian language. This paper shows on quantitative research data the correspondence of the syntax of regional newspapers with the language of all-Russia’s periodicals in the following aspects – the distribution of complex sentences with various types of subordinate clauses in the general system of conditionality and the peculiarities of using the means of their construction. It is shown that in the texts of regional newspapers of Kostroma Region, at the syntactic level, there are all the structural and semantic features of complex sentences with the meaning of conditionality – distribution by their types, the use of typed and non-typed means of communication, the phenomena of gradation, inversion, parcellation, phraseologisation of subordinate clauses. On the example of functioning of the most popular, semantically capacious and significant complex sentences, it is concluded that the syntactic media image of Kostroma Region reflects the general picture in modern Russian journalism, which indicates the stability of the system of complex sentences at the current stage of language development.

A nucleobase-driven P450 peroxidase system enables regio- and stereo-specific formation of C─C and C─N bonds

P450 peroxidase activities are valued for their ability to catalyze complex chemical transformations using economical H2O2; however, they have been largely underexplored compared to their monooxygenase and peroxygenase activities. In this study, we identified an unconventional P450 enzyme, PtmB, which catalyzes the dimerization of purine nucleobases and tryptophan-containing diketopiperazines (TDKPs), yielding C3-nucleobase pyrroloindolines and nucleobase-TDKP dimers. Unlike typical TDKP P450 enzymes reliant on NAD(P)H cofactors and electron transfer systems, PtmB, and its analogs exhibit remarkable peroxidase activity in synthesizing adenine and other modified 6-aminopurine nucleobase-TDKP dimers. Structural analysis of the PtmB-substrate complex, mutation assays, and computational investigations reveal adenine's dual role as both substrate and acid-base catalyst in activating H2O2 to generate Compound I (Cpd I). This initiates a specific radical cascade reaction, facilitating the formation of precise C─C and C─N bonds. Biochemical assays and molecular dynamics simulations demonstrate that adenine's 6-NH2 hydrogen-bonding networks induce necessary conformational changes for H2O2 activation, thereby driving peroxidase activity. This study unveils an unusual catalytic mechanism for the P450 peroxidase system and underscores the pivotal role of nucleobases in enzyme-mediated reactions, which offers different prospects for developing P450 peroxidases and nucleobase-based biocatalysts.

Mutant-selective AKT inhibition through lysine targeting and neo-zinc chelation.

Somatic alterations in the oncogenic kinase AKT1 have been identified in a broad spectrum of solid tumours. The most common AKT1 alteration replaces Glu17 with Lys (E17K) in the regulatory pleckstrin homology domain1, resulting in constitutive membrane localization and activation of oncogenic signalling. In clinical studies, pan-AKT inhibitors have been found to cause dose-limiting hyperglycaemia2-6, which has motivated the search for mutant-selective inhibitors. We exploited the E17K mutation to design allosteric, lysine-targeted salicylaldehyde inhibitors with selectivity for AKT1 (E17K) over wild-type AKT paralogues, a major challenge given the presence of three conserved lysines near the allosteric site. Crystallographic analysis of the covalent inhibitor complex unexpectedly revealed an adventitious tetrahedral zinc ion that coordinates two proximal cysteines in the kinase activation loop while simultaneously engaging the E17K-imine conjugate. The salicylaldimine complex with AKT1 (E17K), but not that with wild-type AKT1, recruits endogenous Zn2+ in cells, resulting in sustained inhibition. A salicylaldehyde-based inhibitor was efficacious in AKT1 (E17K) tumour xenograft models at doses that did not induce hyperglycaemia. Our study demonstrates the potential to achieve exquisite residence-time-based selectivity for AKT1 (E17K) by targeting the mutant lysine together with Zn2+ chelation by the resulting salicylaldimine adduct.

DNAproDB: an updated database for the automated and interactive analysis of protein-DNA complexes.

DNAproDB (https://dnaprodb.usc.edu/) is a database, visualization tool, and processing pipeline for analyzing structural features of protein-DNA interactions. Here, we present a substantially updated version of the database through additional structural annotations, search, and user interface functionalities. The update expands the number of pre-analyzed protein-DNA structures, which are automatically updated weekly. The analysis pipeline identifies water-mediated hydrogen bonds that are incorporated into the visualizations of protein-DNA complexes. Tertiary structure-aware nucleotide layouts are now available. New file formats and external database annotations are supported. The website has been redesigned, and interacting with graphs and data is more intuitive. We also present a statistical analysis on the updated collection of structures revealing salient patterns in protein-DNA interactions.

Preparation of cellulose nano crystals from cinnamon stick, curcumin delivery and interaction with human hemoglobin protein: A novel view of the oxygenation hemoglobin

Curcumin (Cur), a natural phenolic compound, exhibits promising therapeutic properties including anti-cancer and anti-inflammatory effects. However, its limited bioavailability hinders its efficacy when administered alone. To address this challenge, this study explores the use of cellulose nano crystals (CNCs) derived from cinnamon stick via acid hydrolysis as carriers for Cur. The CNCs were thoroughly characterized, and Cur was successfully bound to them. Structural and morphological analyses of the CNCs-Cur complex were investigated applying Fourier-transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Interaction studies between hemoglobin and the CNCs-Cur complex were carried out using various fluorescence spectroscopic techniques. Fluorescence spectroscopy revealed hemoglobin fluorescence quenching by the CNCs-Cur complex, with Stern-Volmer constants determined at different temperatures indicating static mechanism for the quenching. Synchronous fluorescence spectroscopy provided insights into the molecular micro-environment surrounding chromophores, and the distance between the CNCs-Cur complex and hemoglobin fluorophores was calculated using Forster's non-radioactive energy transfer theory (FRET), yielding a distance of less than 7 nm. Circular dichroism (CD) analysis indicated structural changes in hemoglobin upon the interaction with CNCs-Cur, while oxygenation techniques were employed to investigate oxygen binding, release, and transfer in hemoglobin. This comprehensive investigation sheds light on the potential of CNCs as effective carriers for curcumin, offering valuable insights into their interaction with biological molecules.

Supramolecular architectures, Hirshfeld surfaces analysis, spectroscopic, computational and photovoltaic properties of nickel(II) binary and ternary complexes of N-phenethyl-iminodiacetate (2-) chelate

The bluish-green color nickel(II) binary and/or ternary compounds have been isolated from the solution of stoichiometric reaction between Ni(II) hydroxy-carbonate and N-phenethyl-iminodiacetic acid (H2pheida) chelating ligand in aqueous media with compound (2); [Ni(pheida)(Him)3]·4H2O and without imidazole compound (1); [Ni(pheida)(H2O)3]. The crystal pattern of binary compound [Ni(pheida)(H2O)3] (1) differs from the related tetra-hydrated ternary complex of [Ni(pheida)(Him)3]·4H2O (2) can be attributed to the presence of stronger N-(Him) spacer of imidazole ligand. The compounds reported herein, have been characterized by means of elemental analysis, FTIR, UV–vis, TGA and X-ray crystallography. Moreover, the distinctive inter-molecular forces particularly H-bonding interactions, 2D fingerprint plots and supramolecular architecture have been studied using Hirshfeld surface analysis. The nickel(II) binary and ternary complexes (1) and (2) show distorted octahedral geometry around the Ni(II) ion of the type 1 + 2 + 2 + 1 imposed by 3d8 electronic configuration with degenerate fully and half occupied t2g6 and eg2 orbitals respectively. The higher John-Teller distortion has been observed for complex (2) than that of complex (1). The IDA arm of chelate adopted fac-NO2 conformation in both complexes (1) and (2). Moreover, the photovoltaic properties as semiconducting nature for ligand and their corresponding Ni(II) complexes were estimated using Tauc’s equation, αhν = A(hν-Eg)r, where r = ½ for indirect and 2 for direct electronic transitions through UV–vis absorption data. The indirect and direct electronic transition bandgap (Eg) calculated for complex (1) is 2.0 and 3.07 eV respectively. Similarly, 2.55 and 4.39 eV respectively measured for complex (2).

Double Mpemba effect in the cooling of trapped colloids.

The Mpemba effect describes the phenomenon that a system at hot initial temperature cools faster than at an initial warm temperature in the same environment. Such an anomalous cooling has recently been predicted and realized for trapped colloids. Here, we investigate the freezing behavior of a passive colloidal particle by employing numerical Brownian dynamics simulations and theoretical calculations with a model that can be directly tested in experiments. During the cooling process, the colloidal particle exhibits multiple non-monotonic regimes in cooling rates, with the cooling time decreasing twice as a function of the initial temperature-an unexpected phenomenon we refer to as the Double Mpemba effect. In addition, we demonstrate that both the Mpemba and Double Mpemba effects can be predicted by various machine-learning methods, which expedite the analysis of complex, computationally intensive systems.

Deconvoluting the Role of Electrostatics in Metal Carbonyl Bonding: Dipole Moments and Energy Decomposition Analysis of Late Transition Metal Pincer Complexes

Deconvoluting the Role of Electrostatics in Metal Carbonyl Bonding: Dipole Moments and Energy Decomposition Analysis of Late Transition Metal Pincer Complexes

Comparative analysis of tetravalent actinide Schiff base complexes: influence of donor and ligand backbone on molecular geometry and metal binding.

A series of isostructural early actinide AnIV complexes was synthesized in order to investigate the influence of a conjugated framework in the ligand backbone on An bonding. Therefore, the AnIV complexes [An(pyrophen)2] (An = Th, U, Np, and Pu) with the pure N-donor ligand bis(2-pyrrolecarbonylaldehyde)-o-phenylenediamine referred to as pyrophen, were synthesized and characterized. Solid state analysis via single-crystal X-ray diffraction (SC-XRD) reveals two sets of ligands binding in an almost orthogonal arrangement to the actinide center. For the larger actinides Th and U, the coordination sphere allows for additional coordination by a solvent molecule. Nuclear magnetic resonance spectroscopy (NMR) studies show the presence of highly symmetrical complexes in solution in good agreement with the solvent-free solid structures. While SC-XRD suggests mainly ionic binding, an analysis of paramagnetic NMR contributions and quantum chemical bond analysis hint towards significant covalency in the U, Np, and Pu compounds. This series of An complexes allowed for a thorough structural and theoretical comparison of a conjugated system to a closely related N-donor ligand (pyren)[1], as well as to the mixed N,O Schiff base ligands salophen (conjugated) and salen (non-conjugated).

Performance evaluation of a racetrack high temperature superconductor winding in an HTS levitation platform

Abstract High temperature superconducting (HTS) is a key technology of next generation high-speed railway systems, which guarantees high current and highly efficient traction power supply. HTS devices can reduce system weight and thus improve loads of vehicles. On high-speed maglev trains, HTS windings wound by second-generation (2G) HTS tapes play an important role in suspension and traction. However, in complex ferromagnetic environments, the performances of windings are notably influenced by the varying magnetic fields. In this paper, a new maglev platform is designed and comprised of a winding of six racetrack HTS coils, an E shape iron core and a magnetic guide rail. The air core structure of the winding is modeled，tested and the electromagnetic characteristics are analyzed for three dimensional (3D) finite element analysis of the platform. An A formulation is used to calculate magnetic vectors A and infer magnetic flux densities and current densities for the structures. After the winding is installed on the iron core and the magnetic guide rail is suspended above the iron core, the air gap between the iron core and the rail is varied from 0 mm to 20 mm in models and experiments. The magnetic fields, critical currents and losses of the winding in cases of the air core and the iron core conditions are used for analysis. The comparison between the air core and the iron core conditions confirms the reliability of the proposed models. This study provides means for analysis of complex superconducting maglev systems.

Synthesis, Characterization and Studying Thermal Analysis for Complexes of Some Metal Ions and Determining Their Activity as Antioxidants

وفقأ للدراسات السابقة تم تحضير ليكاند آزو جديد (ن-(3-اسيتايل-2-هيدروكسي-5-مثيل-فنيل)ن-(4-كاربوكسي-سايكلوهكسيل مثيل)-ملح الدايازونيوم) وبعد التحقق من الصيغة المقترحة وفق نتائج التحاليل وبعد استخدام الليكاند لتحضير سلسلة ن المعقدات باستخدام نسب مولية متساوية (1:1) من الليكاند وتفاعلها مع كل من املاح المنغنيز والكوبلت والنيكل والنحاس والخارصين وبعد التحقق وفق تقنيات التحاليل الطيفية والتشخيصية(الاشعة فوق البنفسية والاشعة تحت الحمراء) التي اعطت اشكال رباعية السطوح لكل المعقدات بصيغة متعادلة والليكاند ثلاثي السن من نوع (نيتروجين- اوكسجين- اوكسجين) ثم دراسة التحلل الحراري لبعض المركبات المحضرة بتقنية التحليل الوزني الحراري و المسعر التفاضلي مطيافية الكتلة . استخدم الصبغة المعقدات المحضرة منها لتحدد قابليتها على كبح الجذور الحرة من خلال قياس قابليتها كمضادات اكسدة باستخدام مادة DPPHكجذر حر وحامض الاسكوربك كمادة قياسية وتحديد قيمة IC50 حيث وجد ان الليكاند يمتلك قابلية عالية على كبح الجذور الحرة والمعقدات تفاوتت قابليتها على الكبح حسب قيمة IC50وكانت النتائج كما يلي

Investigation of pivalic acid-derived organotin(IV) carboxylates: Synthesis, structural insights, interaction with biomolecules, and computational studies

Herein, six homoleptic and heteroleptic tri-organotin(IV) complexes (1–6) of pivalic acid (HL) were synthesized using 2,2′-bipyridine (bipy) and organotin(IV) chlorides, with a general formula of R3SnL/R3SnLbipy, where R = CH3, C4H9, and C6H5. The structure of the complexes was established in the solid phase via FT-IR spectroscopy and in solution through multinuclear NMR spectroscopy. The variety of coordination modes was implemented by the carboxylate group of pivalic acid, which is reflected in the FT-IR data and also supported by the single crystal XRD analysis for complex 5. The single crystal data revealed the presence of a five-coordinated distorted trigonal bipyramidal geometry for complex 5. The structural and electronic details of the complexes were also evaluated by the application of density functional theory through the Lanl2DZ basis set. The ability of complexes to inhibit the AChE and BChE was assessed in vitro as well as theoretically through molecular docking studies and the results were promising. The complexes 4 and 5 showed high inhibitory potency and could be a potential drug candidate. The DNA binding mode of the complexes was studied using UV–Vis spectroscopy and cyclic voltammetry. The findings revealed that these complexes readily intercalate into DNA via a spontaneous process. Additionally, an effective binding of the complexes with surfactant cetyl trimethyl ammonium bromide (CTAB) through a spontaneous process also proved them valuable in pharmacology.

Chromium Complex of Macrocyclic Ligands as Precursor for Nitric Oxide Release: A Theoretical Study.

Our research on the chromium complex of macrocyclic ligands as a precursor for nitric oxide release makes a significant contribution. We detailed the analysis of nitrito chromium complexes, specifically trans-[M(III)L1-5(ONO)2]+, M=Cr(III) and L1-L5represent different ligands: L1=1,4,8,11-tetraazacyclotetradecane, L2= (5,7-dimethyl-6-benzylcyclam), L3=(5,7-dimethyl-6-anthracylcyclam), L4= (5,7-dimethyl-6-(p-hydroxymethylbenzyl)-1,4, 8,11-cyclam) and L5= (5,7-dimethyl-6-(1¢-methyl-4´-(1"-carboxymethylpyrene) benzyl)-1,4,8,11-tetraazacyclotetradecane). Our objective is to comprehensively understand the mechanism of NO release and identify the key factors influencing NO delivery. The optimized structure of the complexes at spin states S = 1/2 or 3/2 indicates a decrease in the Cr(III)-O bond length (1.669-1.671 Å) along with an increase in the Cr(III)O-NO bond length (2.735 - 2.741 Å), which facilitates the release of NO. Furthermore, there is a significant change in the bond angle (Cr-O-NO), from 120.4° to 116.9°, with respect to S=3/2, thus enlarging theO-NO bond and supporting the β-cleavage of NO from the complex. The calculated activation energy for the complexes reflects the energy difference between the low-spin doublet and high-spin quartet state due to spin crossover (SCO). Moreover, the Natural Transition Orbitals (NTOs) confirm the involvement of a hole-particle in the excitation. Additionally, TD-DFT reveals the pendant chromophore's role in generating NO, as the chromophore antenna effectively enhances light absorption.

Targeting PilA in Acinetobacter baumannii: A Computational Approach for Anti-Virulent Compound Discovery.

Acinetobacter baumannii (A. baumannii) has emerged as a critical global pathogen due to its ability to acquire resistance traits. This bacterium exhibits two distinct forms of motility: twitching, mediated by type IV pili (T4P), and surface-associated motility, independent of appendages. T4P is crucial in various bacterial species, facilitating twitching motility, biofilm formation, and host-cell adhesion. The synthesis of T4P is a common feature among Gram-negative pathogens, particularly A. baumannii, suggesting that PilA could be a viable target for biofilm-related treatments. This study aims to develop drug molecules to mitigate A. baumannii virulence by targeting PilA. Using Schrodinger software, we screened 60,766 compounds from the CMNPD, ChemDiv, and Enamine antibacterial databases through high-throughput virtual screening. The top two compounds from each database, identified through extra precision (XP) mode, were subjected to further studies. Among the six compounds identified (CMNPD18469, CMNPD20698, Z2377302405, Z2378175729, N039-0021, and N098-0051), docking scores ranged from -5.0 to -7.5kcal/mol. Subsequently, we conducted 300ns molecular dynamics simulations and Molecular Mechanics Poisson-Boltzmann Surface Area (MMPBSA) analysis of the PilA-ligand complexes. Analysis of the simulation trajectories indicated structural stability and consistent behavior of the PilA-ligand complexes in a dynamic environment. Notably, the PilA-N098-0051 complex exhibited enhanced stability and robust binding interactions, underscoring its potential as a therapeutic agent. These findings suggest that the identified compounds, particularly N098-0051, hold promise as potent molecules targeting PilA, necessitating further validation through in vitro and in vivo studies.

Investigations of the Cold Box Core Curing Stage Using an Augmented Simulation Approach

AbstractFoundry sand cores are used to produce complex metal castings. They are manufactured on universal coremaking machines in two distinct stages, shooting and curing. Various simulation tools exist to optimize the coremaking process. Numerical modeling of the two distinct process stages is challenging as it involves different tooling, raw materials, and process parameters. Additionally, each stage requires appropriate mathematical modeling of the fluid flow since the relevant physical phenomena are different. The state-of-the-art combined simulation approach (CA) can simulate these two stages in sequence using a Core shooting & curing module. The gassing system (GS) is also important to consider when calculating the complete physical mass flow during the curing stage in CA. An augmented simulation approach (AA) is proposed, which can include GS in the coremaking simulations. This approach enables the execution of two-stage combined simulations (CA) using Magma C + M software (SW1) and incorporates GS data using FLOW-3D CAST software (SW2). In order to analyze the influence of including selected factors such as the hopper during the shooting stage and GS during the curing stage, the simulation approaches CA and AA were compared. The simulation results were correlated with experiment results (EX) to analyze sand density distribution and different curing times, focusing on the final core quality. Quantity analysis has been done among EX samples to observe the cured core trend. The results obtained from AA exhibit a significantly better correlation with EX than with CA. The proposed augmented approach offers significant potential for the improved analysis, optimization, and accurate prediction of complex coremaking processes within polyurethane (PU) Cold Box Systems.

Precision in situ cryogenic correlative light and electron microscopy of optogenetically positioned organelles.

Unambiguous targeting of cellular structures for in situ cryo-electron microscopy in the heterogeneous, dense and compacted environment of the cytoplasm remains challenging. Here, we have developed a cryogenic correlative light and electron microscopy (cryo-CLEM) workflow that utilizes thin cells grown on a mechanically defined substratum for rapid analysis of organelles and macromolecular complexes by cryo-electron tomography (cryo-ET). We coupled these advancements with optogenetics to redistribute perinuclear-localised organelles to the cell periphery, allowing visualisation of organelles that would otherwise be positioned in cellular regions too thick for cryo-ET. This reliable and robust workflow allows for fast in situ analyses without the requirement for cryo-focused ion beam milling. Using this protocol, cells can be frozen, imaged by cryo-fluorescence microscopy and be ready for batch cryo-ET within a day.

Discourse complex <i>i da</i> ‘and yes’ as a dialogue actualizer in modern Russian speech

The article examines semantic and pragmatic features of the discursive complex i da (“and yes”). The relevance of the research is explained by the active inclusion of i da in contemporary speech practice, various genres and styles over the past decade, which was not observed before. The novelty of the research lies in the fact that the element i da becomes the object of linguistic analysis for the first time. This study contributes to the understanding of the discursive complex i da in the context of modern linguistic practices. The findings of this research can be beneficial for further linguistic studies and practical applications. The element i da is not recorded in dictionaries and reference books, which also testifies to the novelty of the material presented in the article, which was extracted from the “National Corpus of the Russian Language”, the electronic media bank “Integrum”. The paper is also based to some degree on the personal observations of the authors. This study provides a fresh perspective on the linguistic element i da, contributing to the existing body of linguistic research. The research was conducted within the framework of the structural and descriptive method using semantic, syntactic, and contextual analysis. As a result, the main discursive role of the complex i da was established, i. e., maintaining the interactive nature of conversation through a ‘delayed response’ mechanism, which allows considering i da as a feedback marker. The discursive complex i da involves a real or potential (in the case of a monologue) interlocutor/opponent in the discourse, performing the role of a dialogic actualizer. The core seme of the complex (‘agreement’) can be explicitly supported by the context, and the addressee of the agreement can be not only the ‘other’ but also the speaker himself. The study reveals the rhetorical potential of i da in monologic speech. This research provides a comprehensive analysis of the discursive complex i da, highlighting its role in dialogic actualization and its rhetorical potential in monologic speech. The variants of punctuation design of the complex i da identified during the research indicate the need for its further study and the creation of a theoretical basis for subsequent codification in punctuation guides. The study proposes a hypothesis about the appearance of i da in Russian as a result of calquing English phrases and yes / and yeah, which are of international nature. This research emphasizes the importance of further investigation into the discursive complex i da, its punctuation variants, and its origins in the Russian language.

Clinical insights into tooth extraction via torsion method: a biomechanical analysis of the tooth-periodontal ligament complex.

Traditionally, extracting single, flat- or curved-rooted teeth through twisting is unfeasible. However, our clinical practice suggests that such teeth can be extracted efficiently through moderate twisting in a minimally invasive manner. Given the lack of studies on biomechanics of the tooth-periodontal ligament (PDL) complex during torsion, which has further constrained its application, we assessed the feasibility of the torsion method for extracting single-rooted teeth and evaluated its minimally invasive potential. Using three-dimensional finite element analysis, we examined the stress distribution of the tooth and PDL during torsion. Then, we examined changes in the optimal torsion angle (OTA) and stress distribution across various anatomical scenarios. During torsion loading, stress concentration was primarily observed on the sing-rooted tooth surface near the alveolar crest, whereas molars at the root furcation. The OTA was found to increase under conditions such as narrowing of root width, decrease in the root apical curvature, change from type I to IV bone, alveolar bone loss, and shortening of root length. Moreover, the clinically validated model demonstrated that 74% of outcomes fell within the standard OTA range. In conclusion, the decrease in PDL area necessitated a larger angle for complete PDL tearing. Single-rooted teeth with root width-to-thickness ratios of ≥0.42 and apical curvatures of ≤30°are suitable for extraction using the torsion method. This study confirms the feasibility of the torsion method for minimally invasive tooth extraction and expands its indications, laying the theoretical foundation and essential insights for its clinical application.

FRACTIONAL ANALYSIS OF POPULATION DYNAMICAL MODEL IN (3+1)-DIMENSIONS WITH FRACTAL-FRACTIONAL DERIVATIVES

The fractal-fractional derivative is a powerful tool that is generally used for the mathematical analysis of complex and unpredictable structures. In this paper, we study a population dynamical model of (3+1)-dimensional form using the fractal derivative involving fractional order with power law kernel. The proposed scheme is known as the Sumudu Homotopy Transform Method ([Formula: see text]HTM), which depends on the association between the Sumudu Transform ([Formula: see text]T) and the Homotopy Perturbation Method (HPM). The convergence of the derived results is verified by comparing the errors in consecutive iterations with the [Formula: see text]HTM results. We display the behavior of the obtained results in three-dimensional shape across the various orders of fractal and fractional derivatives. We present three numerical tests to validate the accuracy of [Formula: see text]HTM and compare the acquired findings to the exact outcomes of the suggested model. This analysis confirms that the [Formula: see text]HTM results align perfectly with the accurate results. As a result, the [Formula: see text]HTM is widely recognized as a leading computational method for obtaining approximate solutions to various nonlinear complex fractal-fractional problems.

N-terminal domain homologs of the orange carotenoid protein increase quenching of cyanobacterial phycobilisomes.

Stress exerted by excess captured light energy in cyanobacteria is prevented by the photoprotective activity of the orange carotenoid protein (OCP). Under high light, the OCP converts from an orange, inactive form (OCPO) into the red form (OCPR) that binds to and quenches the phycobilisome (PBS). Structurally, the OCP consists of two domains: the N-terminal effector domain and a C-terminal regulatory domain. Structural analysis of the OCP-PBS complex showed that the N-terminal domains of an OCP dimer interact with the PBS core. These N-terminal OCP domains have single domain protein paralogs known as Helical Carotenoid Proteins (HCPs). Using phycobilisome quenching assays, we show that the HCP4 and HCP5 homologs efficiently quench PBS fluorescence in vitro, surpassing the quenching ability of the OCP. This is consistent with computational quantum mechanics/molecular mechanics results. Interestingly, when using a maximum quenching concentration of OCP with phycobilisomes, HCP5 addition further increases phycobilisome quenching. Our results provide mechanistic insight into the quenching capacity and roles of HCP4 and HCP5 in cyanobacteria, suggesting that they are more than simply functionally redundant to the OCP.