Structural Research Articles

Taxonomic Implication of Conducting Elements in the Acrocarpous Mosses

Present study deals with the structure and development of conducting elements in the nine orders of acrocarpous mosses. The significance of conducting tissues in mosses in relation to their habitat conditions, growth forms and leaf cell patterns has been discussed. Features of cells in different portions of the stem and the laminal cell patterns and costa are taken into consideration. Although water-conducting cells are unspecialized in mosses, yet the study shows that they seem to play a vital role in the conduction and provide additional criteria for the distinction of taxa. Four categories have been determined as (i) Acrocarpous mosses with a distinct thick-walled conducting strand (6-7 layered) as hydrome which is surrounded by patches of leptoids. Cortex consists of thick walled cells (6-10 layered). Costa has stereidal cells and well developed conducting elements in leaf, example Polytrichum (ii) Acrocarps with thick-walled, narrow, elongated conducting strand (4-5 layered), cells angular in the cortex (6-8 layered). Leaf cells are rectangular, irregular and porous with incrassate walls, example Dicranum (iii) Acrocarps with conducting tissue (2-5 layered) stereidal, thick walled or thin walled varying in the course of development. Leaf cells are mutipapillate, rounded-quadrate, costa is present, examples Hyophila, Philonotis and (iv) Epiphytic pleurocarps with conducting cells rudimentary, thickened, scattered (2-4 layers) and parenchymatous, cortical cells (2-3 layered) thick walled. Leaf cells are small, rounded or linear and papillate, costa may be present or absent, example Leucodon . The study would constitute a formidable task, especially if intraspecific structural variability is considered. It serves a model system in the eco-physiological aspects.

Critical influence of vegetation response to rising CO2 on runoff changes

Satellite observations show widespread greening over the global land, which potentially contributes to runoff (R) changes. However, there are discrepancies in the impacts of vegetation greening on R under elevated atmospheric CO2 concentration (eCO2). Here, we proposed an improved Budyko framework with full consideration of the vegetation structural (STR) effect and vegetation physiological (PHY) effect and evaluated runoff changes (ΔR) due to eCO2-induced vegetation variations. We found a better performance of the improved Budyko framework in simulating runoff changes from global climate models (the Nash-Sutcliffe efficiency coefficient (NSE) is 0.82). However, ΔR would be overestimated (underestimated) by 188 % (165 %) when considering the PHY (STR) effect only. Attribution analyses indicated that PHY and STR effects contribute to a ΔR of 12.8 % and − 62 %, respectively, suggesting that PHY and STR effects are indispensable variables in the projection of ΔR. The contribution of the STR effect to future ΔR is 4.8 times larger than the PHY effect, leading to a negative effect of vegetation changes on ΔR in response to eCO2. While the magnitude of PHY appears less than that of STR, the influence of PHY on ΔR follows a faster-increasing tendency in future R projections when compared to STR. Our findings emphasize the critical influence of vegetation response to eCO2 in future R projection.

Assessing the role of central lymph node ratio in predicting recurrence in N1a low-to-intermediate risk papillary thyroid carcinoma.

Lymph node metastasis in patients with papillary thyroid carcinoma (PTC) is associated with postoperative recurrence. Recently, most studies have focused on the evaluation of recurrence in patients with late-stage PTC, with limited data on those with early-stage PTC. We aimed to assess the relationship between lymph node ratio (LNR) and recurrence in low-to-intermediate-risk patients and validate its diagnostic efficiency in both structural (STR) and biochemical recurrence (BIR). Clinical data of patients with PTC diagnosed at the Affiliated Hospital of Jining Medical University were retrospectively collected. The optimal LNR cut-off values for disease-free survival (DFS) were determined using X-tile software. Predictors were validated using univariate and multivariate Cox regression analyses. LNR had a higher diagnostic effectiveness than metastatic lymph nodes in patients with low-to-intermediate recurrence risk N1a PTC. The optimal LNR cutoff values for STR and BIR were 0.75 and 0.80, respectively. Multivariate Cox regression analysis showed that LNR≥0.75 and LNR≥0.80 were independent factors for STR and BIR, respectively. The 5-year DFS was 90.5% in the high LNR (≥0.75) and 96.8% in low LNR (<0.75) groups for STR. Regarding BIR, the 5-year DFS was 75.7% in the high LNR (≥0.80) and 86.9% in low LNR (<0.80) groups. The high and low LNR survival curves exhibited significant differences on the log-rank test. LNR was associated with recurrence in patients with low-to-intermediate recurrence risk N1a PTC. We recommend those with LNR≥0.75 require a comprehensive evaluation of lateral neck lymphadenopathy and consideration for lateral neck dissection and RAI treatment.

Structural-functional connectivity bandwidth predicts processing speed in mild traumatic brain Injury: A multiplex network analysis

An emerging body of work has revealed alterations in structural (SC) and functional (FC) brain connectivity following mild TBI (mTBI), with mixed findings. However, these studies seldom integrate complimentary neuroimaging modalities within a unified framework. Multilayer network analysis is an emerging technique to uncover how white matter organization enables functional communication. Using our novel graph metric (SC-FC Bandwidth), we quantified the information capacity of synchronous brain regions in 53 mild TBI patients (46 females; age mean = 40.2 years (y), σ = 16.7 (y), range: 18–79 (y). Diffusion MRI and resting state fMRI were administered at the acute and chronic post-injury intervals. Moreover, participants completed a cognitive task to measure processing speed (30 Seconds and Counting Task; 30-SACT). Processing speed was significantly increased at the chronic, relative to the acute post-injury intervals (p = <0.001). Nonlinear principal components of direct (t = -1.84, p = 0.06) and indirect SC-FC Bandwidth (t = 3.86, p = <0.001) predicted processing speed with a moderate effect size (R2 = 0.43, p < 0.001), while controlling for age. A subnetwork of interhemispheric edges with increased SC-FC Bandwidth was identified at the chronic, relative to the acute mTBI post-injury interval (pFDR = 0.05). Increased interhemispheric SC-FC Bandwidth of this network corresponded with improved processing speed at the chronic post-injury interval (partial r = 0.32, p = 0.02). Our findings revealed that mild TBI results in complex reorganization of brain connectivity optimized for maximum information flow, supporting improved cognitive performance as a compensatory mechanism. Moving forward, this measurement may complement clinical assessment as an objective marker of mTBI recovery.

Active Outward Orientation of the Organisation

A central problem of organisations is the uncertainty of their environmental transactions in the attainment of desired responses. The degree to which the uncertainty is reduced, is often associated with the organisation's offectiveness. This study examines and Identifies an appropriate theoretical framework within which to proceed with an Investigation into organisational effectiveness. The systems approach, although of limited ontological value, of. fers a valuable cluster of strategies for Inquiry, within which Heldema's partial. dy systems-derived view is discussed. According to this view, perceptions of real systems can be described along spatial and temporal dimensions: as ahistorical, Inward-looking and struc tural; or as historical, outward-looking and changing. From this, the active out. ward orlented perceptual paradigm is developed, and It Is suggested that the existence of the active outward oriented basic assumption is a necessary condition of the organisation's potential effectiveness, and that the process by which it is instituted and maintained is communication.

Combination of structural and functional connectivity explains unique variation in specific domains of cognitive function

The relationship between structural and functional brain networks has been characterised as complex: the two networks mirror each other and show mutual influence but they also diverge in their organisation. This work explored whether a combination of structural and functional connectivity can improve the fit of regression models of cognitive performance. Principal Component Analysis (PCA) was first applied to cognitive data from the Human Connectome Project to identify latent cognitive components: Executive Function, Self-regulation, Language, Encoding and Sequence Processing. A Principal Component Regression approach with embedded Step-Wise Regression (SWR-PCR) was then used to fit regression models of each cognitive domain based on structural (SC), functional (FC) or combined structural-functional (CC) connectivity. Executive Function was best explained by the CC model. Self-regulation was equally well explained by SC and FC. Language was equally well explained by CC and FC models. Encoding and Sequence Processing were best explained by SC. Evaluation of out-of-sample models’ skill via cross-validation showed that SC, FC and CC produced generalisable models of Language performance. SC models performed most effectively at predicting Language performance in unseen sample. Executive Function was most effectively predicted by SC models, followed only by CC models. Self-regulation was only effectively predicted by CC models and Sequence Processing was only effectively predicted by FC models. The present study demonstrates that integrating structural and functional connectivity can help explaining cognitive performance, but that the added explanatory value (in-sample) may be domain-specific and can come at the expense of reduced generalisation performance (out-of-sample).

Functional modular organization unfolded by chimera-like dynamics in a large-scale brain network model

The brain is organized as a complex network architecture, which can be mapped into structural (SC) and functional connectivity (FC) by advanced neuroimaging techniques. Achievements in brain network research have revealed that modularity is a universal trait in brain networks and may be vital for cognitive segregation and integration. Large-scale brain network modeling is a promising computational approach to combine neuroimaging data with generative rules for brain dynamics. Recently, it has been proposed that chimera states, a type of dynamics referring to the coexistence of coherent and incoherent participants, have traits in common with cognitive functions like segregated and integrated brain processing. Previous studies have reported the existence of chimera-like dynamics in large-scale brain network models, whereas they did not account for the relationship between chimera-like dynamics and corresponding functional modular organizations of the brain network. By specifying qualitatively different network dynamics in an anatomically-constrained brain network model, we compare the different modular organizations of FC unfolded by network dynamics. Our simulations reveal that chimera-like dynamics support a meaningful pattern of functional modular organization, which promotes a diversity of node roles with a distributed pattern of functional cartography. The distinct node roles in modular FC are also found to occur with a spatial preference in specific brain regions, and, to some extent, reflect the underlying structure constraints. Our results support the view that chimera-like dynamics is a functionally meaningful scenario that may play a fundamental role in the segregation and integration of brain functioning.

Reliability and subject specificity of personalized whole-brain dynamical models

Dynamical whole-brain models were developed to link structural (SC) and functional connectivity (FC) together into one framework. Nowadays, they are used to investigate the dynamical regimes of the brain and how these relate to behavioral, clinical and demographic traits. However, there is no comprehensive investigation on how reliable and subject specific the modeling results are given the variability of the empirical FC. In this study, we show that the parameters of these models can be fitted with a ”poor” to ”good” reliability depending on the exact implementation of the modeling paradigm. We find, as a general rule of thumb, that enhanced model personalization leads to increasingly reliable model parameters. In addition, we observe no clear effect of the model complexity evaluated by separately sampling results for linear, phase oscillator and neural mass network models. In fact, the most complex neural mass model often yields modeling results with ”poor” reliability comparable to the simple linear model, but demonstrates an enhanced subject specificity of the model similarity maps. Subsequently, we show that the FC simulated by these models can outperform the empirical FC in terms of both reliability and subject specificity. For the structure-function relationship, simulated FC of individual subjects may be identified from the correlations with the empirical SC with an accuracy up to 70%, but not vice versa for non-linear models. We sample all our findings for 8 distinct brain parcellations and 6 modeling conditions and show that the parcellation-induced effect is much more pronounced for the modeling results than for the empirical data. In sum, this study provides an exploratory account on the reliability and subject specificity of dynamical whole-brain models and may be relevant for their further development and application. In particular, our findings suggest that the application of the dynamical whole-brain modeling should be tightly connected with an estimate of the reliability of the results.

Вплив препарату мебівід на структурно-функціональний стан кісткової тканини при аліментарному остеопорозі в експерименті

З метою визначення впливу на нормалізацію структурно-функціонального стану епіфізарного хряща та кісткової тканини вітчизняного комплексного препарату мебівід, що містить у складі вітамін D3 та бісфосфонат, проведено експериментальне дослідження на 30 щурах лінії Вістар масою 90 ± 5 г. Було використано аліментарну модель остеопорозу. Проводилися гістоморфологічне та остеометричне дослідження, визначалась зольність кісток. За результатами дослідження виявлено, що мебівід ефективно впливає на нормалізацію порушень структурно-функціонального стану епіфізарного хряща та кісткової тканини при аліментарному остеопорозі в щурів. Експериментальні дослідження доводять доцільність застосування комплексного препарату мебівід у лікуванні ортопедичних захворювань, що супроводжуються порушеннями повздовжнього росту, росту в товщину та структурно-функціонального стану кісткової тканини.

ANALISIS STRATEGI CITRA MEREK DALAM MENINGKATKAN KEPUASAN PELANGGAN OCTO MOBILE

The purpose of this study was to determine the effect of promotion, service quality, and innovation directly or indirectly on Brand Image, as well as the effect of all these variables on OCTO Mobile customer satisfaction. The research sample was 385 respondents who were CIMB Niaga customers. The sampling technique was purposive sampling—data collection using a questionnaire and FGD. The data analysis technique used Structural Equation Modeling (SEM) analysis which aided with SmartPLS software. The study results prove that the variables of service quality and innovation have a significant effect on brand image and brand image has no significant effect on customer satisfaction. However, the promotion variable does not have a significant effect on brand image. Promotion variables, service quality, and innovation significantly affect customer satisfaction, while the brand image variable has no significant effect on customer satisfaction. The results also show the customer satisfaction strategy plan by referring to the strategies from the analysis that has been done, and the right strategy is selected, namely product development.

Seismic probabilistic risk assessment of weir structures considering the earthquake hazard in the Korean Peninsula

Seismic safety evaluation of weir structure is significant considering the catastrophic economical consequence of operational disruption. In recent years, the seismic probabilistic risk assessment (SPRA) has been issued as a key area of research for the hydraulic system to mitigate and manage the risk. The aim of this paper is to assess the seismic probabilistic risk of weir structures employing the seismic hazard and the structural fragility in Korea. At the first stage, probabilistic seismic hazard analysis (PSHA) approach is performed to extract the hazard curve at the weir site using the seismic and geological data. Thereafter, the seismic fragility that defines the probability of structural collapse is evaluated by using the incremental dynamic analysis (IDA) method in accordance with the four different design limit states as failure identification criteria. Consequently, by combining the seismic hazard and fragility results, the seismic risk curves are developed that contain helpful information for risk management of hydraulic structures. The tensile stress of the mass concrete is found to be more vulnerable than other design criteria. The hazard deaggregation illustrates that moderate size and far source earthquakes are the most likely scenario for the site. In addition, the annual loss curves for two different hazard source models corresponding to design limit states are extracted.

Значення променевих методів дослідження при вивченні структурно-функціонального стану стегнової кістки при дисплазії кульшового суглоба в дітей раннього віку (огляд літератури)

У статті наведено огляд існуючих методів променевого дослідження структурно-функціонального стану кісткової тканини в дітей раннього віку. Відомо, що в дітей навіть у нормі зустрічаються остеопенічні стани, причину яких не завжди можливо встановити. У низці випадків вони можуть бути зумовлені недорозвинен-ням кісткової тканини відповідно до віку, що характерно для різних видів дисплазій, а дисплазія кульшового суглоба — найчастіша ортопедична патологія дитячого віку. У літературі не наведені нормативні показники мінеральної щільності кісткової тканини для стегнової кістки в дітей раннього віку, а в багатьох зарубіжних і вітчизняних публікаціях показана необхідність створення національних референтних баз даних для кожної окремо взятої країни. Установлені показники вікової норми дозволять більш об’єктивно оцінювати стан кісткової тканини, адекватно і своєчасно виявляти втрату кісткової маси та формувати групи ризику щодо розвитку остеопорозу в старшому віці.

O uso do bambu como material estrutural na construção civil

&lt;p&gt;A construção civil é responsável por gerar grandes impactos ambientais, fazendo-se necessário adotar alternativas que reduzam essa problemática e atendam ao desenvolvimento sustentável. Entre as alternativas, destaca-se a substituição dos materiais convencionais por outros mais limpos, a exemplo do bambu. Trata-se de um vegetal de rápido desenvolvimento, com propriedades e potencialidade para ser utilizado na construção civil. Devido à sua elevada resistência à tração, torna-se equiparável ao aço. Partindo desse princípio, a presente pesquisa exploratória de método qualitativo apresenta como objetivo abordar o uso do bambu como material estrutural na construção civil. Por meio de uma metodologia de cunho bibliográfico, explicita-se as propriedades, os benefícios e as limitações do bambu na construção civil. Além disso, para melhor exemplificar o uso do bambu como material estrutural, foram expostas construções com esse material, como também, por meio de um questionário, foi realizada uma análise da sua utilização na construção civil no Brasil. Desse modo, verifica-se que o bambu é um material que detém propriedades úteis para ser utilizado na construção civil. Entretanto, no Brasil, sua utilização ainda não ocorre de forma ampla, devido a fatores que limitam o seu uso. &lt;strong&gt;&lt;/strong&gt;&lt;/p&gt;

Структурні зміни слизової оболонки шлунка в пацієнтів iз кишковою метаплазією та гіперпродукцією оксиду азоту

Мета: проаналізувати структурні зміни слизової оболонки шлунка та оцінити роль системи оксиду азоту в цих процесах у пацієнтів iз хронічним гастритом та кишковою метаплазією. Матеріали та методи. Морфологічне дослідження проводилося в 38 пацієнтів iз хронічним гастритом та атрофією, локальною (антральний відділ шлунка) або дифузною кишковою метаплазією. Концентрація оксиду азоту була визначена у вмісті шлунка та в крові всіх пацієнтів. Результати. Морфометричне дослідження показало помітне зниження (до (0,12 ± 0,04) %) ядерно-цитоплазматичного співвідношення в пацієнтів iз кишковою метаплазією порівняно з тими, хто мав атрофію. Еліптичність ядер клітин також зменшувалася з розвитком кишкової метаплазії та в пацієнтів без метапластичних змін дорівнювала (0,76 ± 0,04) %, у випадках локальної кишкової метаплазії — (0,65 ± 0,11) %, при дифузнiй метаплазії — (0,41 ± 0,12) %. Встановлено, що у хворих iз кишковою метаплазією, локалiзованою в антральному відділі, рівень оксиду азоту в шлунковому соку збільшується і на 24–65 % перевищує контрольну величину. Розглянуто можливий механізм загибелі клітин слизової оболонки шлунка внаслiдок апоптозу та некрозу в умовах гіперпродукції оксиду азоту. Висновки. Iнгібуючий ефект оксиду азоту на шлункову секрецію реалізується за рахунок його стимулюючого впливу на активність циклооксигенази та синтезу простагландинів.

Alguns contributos das Neurociências para a Educação: Os ambientes enriquecidos aumentam a capacidade de aprendizagem do nosso cérebro?

A reflexão e a discussão sobre o papel da especificação genética e da experiência na aquisição de uma função e no desenvolvimento de um indivíduo traduz um debate fascinante e muito atual entre quem trabalha na área do desenvolvimento do comportamento. Acerca do desenvolvimento do comportamento humano e da influência da herança biológica e do meio ambiente estabeleceram-se posições desencontradas e, por vezes, exclusivistas. De um lado, os adeptos da herança genética excluem a possibilidade da influência do meio ambiente. Do outro lado, os adeptos do meio ambiente excluem a herança genética. Existe também uma posição eclética, conciliando ambos os extremos. Além disso, no âmbito das próprias tendências surgem matizes diferenciadoras. Trata-se, portanto, de um assunto bastante polémico ao qual dedicamos este trabalho numa perspetiva das Neurociências. Abordaremos a neuroplasticidade cerebral como a capacidade que o sistema nervoso possui de mudar e adaptar-se, em resposta a estímulos internos e externos, induzindo alterações estruturais e / ou funcionais, ao longo da vida. A plasticidade cerebral constitui um dos pilares dos processos de aprendizagem e de memória. Quando se aprende e se memoriza ou quando se descobre algo desconhecido, a nova experiência deixa uma marca que se traduz em alterações no cérebro. Em suma, o papel das Neurociências no domínio das Ciências da Educação vai ganhando corpo e o conceito de neuroplasticidade é uma condição sine qua non para se tentar estabelecer uma ligação entre a educação, o comportamento e o cérebro.

Synthesis and antimicrobial activity of some quinoxaline derivatives

Some new structural motifs containing the quinoxaline nucleus have been synthesized and examined for their pharmacological properties. In this study, 6-chloroquinoxaline-2,3(1H, 4H)-dione and 6 nitroquinoxaline-2,3(1H, 4H)-dione were synthesized as basic nuclei for the preparation of the new quinoxaline-2,3-diones by alkylation reactions under the conditions of phase transfer catalysis. The products were characterized by spectroscopic methods 1 H and 13 C NMR. Then, the synthesized products were tested for their antibacterial effects against two bacterial strains. The values of minimum inhibitory concentrations (MIC) vary according to the nature of the alkyl bonded to the quinoxaline nucleus.

Investigation of progressive collapse in reinforced concrete buildings with slab-wall structural system

Nowadays, Reinforced Concrete (RC) wall-slab systems are being used more extensively due to their effective performance seen in past earthquakes. Progressive collapse is a phenomenon in which all or part of a structure is damaged due to damage or collapse of a small relevant part. The majority of research done in the field of progressive collapse has been on frame-shaped structures. Further, the performance of RC wall-slab structural systems, especially against progressive collapse, has been less studied. In this study, at first, nine concrete buildings of five, ten and fifteen stories with wall-slab structural systems, with the ratio of spans length to the story height (L/H) of 1, 1.5 and 2 and a structural height of 2.75 meters in each story, were designed by the ETABS V16 software. Then, using the SAP2000 software and nonlinear shell-layered elements, nonlinear static analysis was performed by the Alternative Load Path (ALP) method on the models and the results were evaluated. The results demonstrated the relatively high strength of buildings with wall-slab structural systems in withstanding progressive collapse. The rate of vertical displacement of the removal location, the maximum von Mises stress in rebar, the maximum compressive stress and strain in concrete in the interior wall removal scenarios were less extensively compared to the corner wall removal scenarios. In contrast, progressive collapse potential increased significantly with increasing number of stories and the L/H ratio. Also, it was found that, buildings with the wall-slab structural system may exhibit brittle failure behavior influenced by progressive collapse.

Transistores de Película Delgada Basados en Oxido de Zinc por Spray Pyrolysis Ultrasónico de Alta Frecuencia a Baja Temperatura

En este artículo, se reporta la fabricación de transistores de película delgada con óxido de zinc (ZnO TFTs) sobre sustratos de plástico por spray pyrolysis ultrasónico de alta frecuencia a baja temperatura. La máxima temperatura de fabricación fue de 200°C. Spin-on glass fue usado como dieléctrico de compuerta. El tereftalato de polietileno (PET) es usado como sustrato de plástico. Los ZnO TFTs exhiben una movilidad de electrones de 1.25 cm2/Vs y voltaje de umbral de 10.5V, mientras la relación de corriente on/off fue de 104. Adicionalmente, la densidad de trampas en la capa activa y en la interfaz dieléctrico/semiconductor son calculados. Además, capacitores metal-dieléctrico-metal fueron fabricados sobre plástico y caracterizados para evaluar el dieléctrico de compuerta.

Памяти Александра Сергеевича Илюшина

Provides information about the deceased Alexander Sergeevich Ilyushin - Doctor of Physical and Mathematical Sciences, professor, Head of the Chair of Solid State Physics, Faculty of Physics, Lomonosov Moscow State University, Honored Professor of Lomonosov MSU, a full member of the Russian Academy of Natural Sciences, a well-known specialist in the field of structural solid state physics: basic biographical data, training at the Physics Faculty of Lomonosov MSU, postgraduate studies and work at the Solid State Physics Chair of Moscow State University, defense of candidate and doctoral dissertations, authorship of hundreds of scientific works, dozens of monographs and textbooks, pedagogical activity, leadership of the Solid State Physics Chair of MSU, membership in the academic councils of the Physics Faculty, participation and organization of Russian and international conferences, editorial scientific journals, creation and management of the Museum of History of the Physics Faculty of MSU, membership in the Russian Academy of Natural Sciences, management of its Division, creation and management of the Union of Philatelists of Russia, participation and organization of Russian and international philatelic exhibitions and conferences.

Disauerstoffaktivierung und Pyrrol‐α‐Spaltung mit Calix[4]pyrrolatoaluminaten: Enzymmodell durch strukturellen Zwang

AbstractDie vorliegende Arbeit beschreibt die Reaktion von Triplett‐Disauerstoff mit den porphyrinogenen Calix[4]pyrrolatoaluminaten hin zu Alkylperoxidoaluminaten mit hoher Selektivität. Multikonfigurationsquantenchemische Berechnungen beleuchten den spinverbotenen Prozess. Ungeachtet einer vernachlässigbaren Spin‐Bahn‐Kopplungskonstante wird die Interkombination (intersystem crossing) durch die Entartung des Singulett‐ und Triplett‐Zustands sowie durch spinvibronische Kopplung ermöglicht. Die gebildeten Peroxide sind stabil gegenüber externen Substraten, gehen allerdings eine beispiellose oxidative Pyrrol‐α‐Spaltung mittels einer durch Ligand‐Aromatisierung/‐dearomatisierung initiierten Spaltung der O‐O‐σ‐Bindung ein. Ein detaillierter Vergleich der Calix[4]pyrrolatoaluminate mit disauerstoffbezogener Enzymologie liefert Einblicke in die Arbeitsweise von metall‐ und cofaktorfreien Enzymen. Diese Zusammenhänge bekräftigen die Wichtigkeit von strukturellem Zwang und Element‐Ligand‐Kooperativität für die Funktionen des aeroben Lebens.