Complex Hierarchical Structure Research Articles

Quantitative Ultrashort Echo Time (UTE) Magnetic Resonance Imaging of Bone: An Update.

Bone possesses a highly complex hierarchical structure comprised of mineral (~45% by volume), organic matrix (~35%) and water (~20%). Water exists in bone in two forms: as bound water (BW), which is bound to bone mineral and organic matrix, or as pore water (PW), which resides in Haversian canals as well as in lacunae and canaliculi. Magnetic resonance (MR) imaging has been increasingly used for assessment of cortical and trabecular bone. However, bone appears as a signal void on conventional MR sequences because of its short T2*. Ultrashort echo time (UTE) sequences with echo times (TEs) 100–1,000 times shorter than those of conventional sequences allow direct imaging of BW and PW in bone. A series of quantitative UTE MRI techniques has been developed for bone evaluation. UTE and adiabatic inversion recovery prepared UTE (IR-UTE) sequences have been developed to quantify BW and PW. UTE magnetization transfer (UTE-MT) sequences have been developed to quantify collagen backbone protons, and UTE quantitative susceptibility mapping (UTE-QSM) sequences have been developed to assess bone mineral.

Third International Conference “Physics for Life Sciences” Study of Dentin Structural Features by Computed Microtomography and Transmission Electron Microscopy

Dentin in the human tooth is a natural composite material with a complex multilevel hierarchical structure and consists of micro and nanostructures that are related to each other in a complex interrelation governed by laws that have not been fully understood yet. To identify the relationship between the dentin structure and its mechanical properties, we study samples prepared from human molars after subjecting them to uniaxial compression. Elements of dentin matrix and microtubules passing through it are investigated by transmission electron microscopy and computed microtomography using synchrotron light. Some structural features arising from the interaction between the elements and the dentin tubule properties that lead to arrest of crack propagation are investigated. We develop a theoretical model that can be used to identify the conditions for mode II crack inhibition due to opening of satellite cracks by stresses present on the surface of dentin tubules.

A novel machine learning strategy for model selections - Stepwise Support Vector Machine (StepSVM).

An essential aspect of medical research is the prediction for a health outcome and the scientific identification of important factors. As a result, numerous methods were developed for model selections in recent years. In the era of big data, machine learning has been broadly adopted for data analysis. In particular, the Support Vector Machine (SVM) has an excellent performance in classifications and predictions with the high-dimensional data. In this research, a novel model selection strategy is carried out, named as the Stepwise Support Vector Machine (StepSVM). The new strategy is based on the SVM to conduct a modified stepwise selection, where the tuning parameter could be determined by 10-fold cross-validation that minimizes the mean squared error. Two popular methods, the conventional stepwise logistic regression model and the SVM Recursive Feature Elimination (SVM-RFE), were compared to the StepSVM. The Stability and accuracy of the three strategies were evaluated by simulation studies with a complex hierarchical structure. Up to five variables were selected to predict the dichotomous cancer remission of a lung cancer patient. Regarding the stepwise logistic regression, the mean of the C-statistic was 69.19%. The overall accuracy of the SVM-RFE was estimated at 70.62%. In contrast, the StepSVM provided the highest prediction accuracy of 80.57%. Although the StepSVM is more time consuming, it is more consistent and outperforms the other two methods.

Long-term changes in endemic threshold populations for pertussis in England and Wales: A spatiotemporal analysis of Lancashire and South Wales, 1940-69

Metapopulation dynamics play a critical role in driving endemic persistence and transmission of childhood infections. The endemic threshold concept, also referred to as critical community size (CCS), is a key example and is defined as the minimum population size required to sustain a continuous chain of infection transmission. The concept is fundamental to the implementation of effective vaccine-based disease control programmes. Vaccination serves to increase endemic threshold population size, promoting disease fadeout and eventual elimination of infection. To date, empirical investigations of the relationship between vaccination and endemic threshold population size have tended to focus on isolated populations in island communities. Very few studies have examined endemic threshold dynamics in ‘mainland’ regional populations with complex hierarchical spatial structures and varying levels of connectivity between subpopulations. The present paper provides the first spatially explicit analysis of the temporal changes in endemic threshold populations for one vaccine-preventable childhood infection (pertussis) in two dynamic regions of England and Wales: Lancashire and South Wales. Drawing upon weekly disease records of the Registrar-General of England and Wales over a 30-year period (January 1940–December 1969) regression techniques were used to estimate the endemic threshold size for pertussis in the two study regions. Survival analyses were performed to compare disease fadeout duration and probability for both regions in the pre-vaccine and vaccine eras, respectively. Our findings reveal the introduction of mass vaccination led to a considerable increase in threshold size for both Lancashire (~387,333) and South Wales (~1,460,667). Significant growth in fadeout duration was observed in the vaccine era for pertussis non-hotspots in both regions, consistent with geographical synchronisation of epidemic activity. Regional differences in endemic threshold populations reflect significant regional variations in spatial connectivity, population dispersion and level of geographical isolation.

Depthwise and Spatial Factorized Network: a Light-weight Network for Real-time Semantic Segmentation

Real-time semantic segmentation requires high quality output in relatively short computing time. The existing deep neural network model usually has complex hierarchical structure and a large number of parameters. For the application of real-time computing, the network has higher requirements for computing performance. To address the speed and accuracy trade-off, a novel structure, named Depthwise and Spatial Factorized Network (DSFNet) is proposed in this paper. In DSFNet, two important strategies are introduced. Firstly, Depthwise and Spatial Factorized Convolution is used to reduce the number of parameters in encoder network remarkably. After that, residual attention mechanism is utilized in decoder with a fast downsampling strategy to obtain sufficient receptive field. These two strategies make the process of upsampling more precisely and achieve better performance. Comprehensive experiments on Cityscapes dataset verify the effectiveness of the proposed DSFNet. The DSFNet achieves 63.08 mIoU at 58 FPS with residual attention mechanism.

Recursive music elucidates neural mechanisms supporting the generation and detection of melodic hierarchies

The ability to generate complex hierarchical structures is a crucial component of human cognition which can be expressed in the musical domain in the form of hierarchical melodic relations. The neural underpinnings of this ability have been investigated by comparing the perception of well-formed melodies with unexpected sequences of tones. However, these contrasts do not target specifically the representation of rules generating hierarchical structure. Here, we present a novel paradigm in which identical melodic sequences are generated in four steps, according to three different rules: The Recursive rule, generating new hierarchical levels at each step; The Iterative rule, adding tones within a fixed hierarchical level without generating new levels; and a control rule that simply repeats the third step. Using fMRI, we compared brain activity across these rules when participants are imagining the fourth step after listening to the third (generation phase), and when participants listened to a fourth step (test sound phase), either well-formed or a violation. We found that, in comparison with Repetition and Iteration, imagining the fourth step using the Recursive rule activated the superior temporal gyrus (STG). During the test sound phase, we found fronto-temporo-parietal activity and hippocampal de-activation when processing violations, but no differences between rules. STG activation during the generation phase suggests that generating new hierarchical levels from previous steps might rely on retrieving appropriate melodic hierarchy schemas. Previous findings highlighting the role of hippocampus and inferior frontal gyrus may reflect processing of unexpected melodic sequences, rather than hierarchy generation per se.

Zero-shot Handwritten Chinese Character Recognition with hierarchical decomposition embedding

Handwritten Chinese Character Recognition (HCCR) is a challenging topic in the field of pattern recognition due to large-scale character vocabulary, complex hierarchical structure, various writing styles, and scarce training samples. In this paper, we explored the hierarchical knowledge of Chinese characters and presented a novel zero-shot HCCR method. First, we handled the relations between the characters and their primitives, such as radicals and structures, to obtain a tree layout of primitives. Then, we presented a novel zero-shot hierarchical decomposition embedding method to encode the tree layout into a semantic vector. Next, we devised a Convolutional Neural Network (CNN) based framework to learn both radicals and structures of characters via the semantic vector. As different Chinese characters share some common radicals and structures, our method is able to recognize new categories without any labeled samples from them. Moreover, our method is effective in both traditional HCCR and zero-shot HCCR tasks. It achieves competitive performance on the traditional experiment setting and significantly surpasses the state-of-the-art methods on the zero-shot experiment setting.

P0658MATRIX AND FLOW MODULATE GENE EXPRESSION IN A 3D VASCULARISED TUBULE MODEL

Abstract Background and Aims Questions abound regarding the translation of in vitro 2D cell culture systems to the human setting. This is especially true of the kidney in which there is a complex hierarchical structure and a multitude of cell types. While it is well accepted that extracellular matrix plays a large part in directing cellular physiology emerging research has highlighted the importance of shear stresses and flow rates too. To fully recapitulate the normal gene expression and function of a particular renal cell type how important is it to completely reconstitute their in vivo surroundings? Method To answer this question, we have cultured proximal tubular (PT) epithelial cells in a 3-dimensional channel embedded within an engineered extracellular matrix (ECM) under physiological flow that is colocalised with an adjacent channel lined with renal microvascular endothelial cells that mimic a peritubular capillary. Modifications to the system were made to allow up to 12 chips to be run in parallel in an easily handleable form. After a period of maturation under continuous flow, both cell types were harvested for RNAseq analyses. RNA expression data was compared with cells cultured under static 2-dimensional conditions on plastic or the engineered ECM. Additionally, the perfusion of glucose through this 3D vascularised PT model has been investigated in the presence and absence of known diabetes modulating agents. Results PCA of RNAseq data showed that a) static non-coated, b) static matrix-coated and c) flow matrix-coated conditions separated into 3 distinct groups, while cell co-culture had less impact. Analysis of transcriptomic signatures showed that many genes were modulated by the matrix with additional genes influenced under flow conditions. Several of these genes, classified as transporters, are of particular importance when using this model to assess drug uptake and safety implications. Co-culture regulated some interesting genes, but fewer than anticipated. Preliminary experiments are underway to monitor glucose uptake and transport between tubules under different conditions. Conclusion We have developed a medium throughput system in which matrix and flow modulate gene expression. This system can be used to study the physiology of molecular cross-talk between cells. Ongoing analysis will further consider relevance to human physiology.

Porous Poly(3-hydroxybutyrate) Scaffolds Prepared by Non-Solvent-Induced Phase Separation for Tissue Engineering.

Highly porous poly(3-hydroxybutyrate) (PHB) scaffolds were fabricated using non-solvent-induced phase separation with chloroform as the solvent and tetrahydrofuran as the non-solvent. The microporosity, nanofiber morphology, and mechanical strength of the scaffolds were adjusted by varying the fabrication parameters, such as the polymer concentration and solvent composition. The influence of these parameters on the structure and morphology of PHB organogels and scaffolds was elucidated using small-angle neutron scattering and scanning electron microscopy. The organogels and scaffolds in this study have a complex hierarchical structure, extending over a wide range of length scales. In vitro viability assays were performed using the human keratinocyte cell line (HaCaT), and all PHB scaffolds demonstrated the excellent cell viability. Microporosity had the greatest impact on HaCaT cell proliferation on PHB scaffolds, which was determined after a 3-day incubation period with scaffolds of different morphologies and mechanical properties. The superior cell viability and the controlled scaffold properties and morphologies suggested PHB scaffolds fabricated by non-solvent-induced phase separation using chloroform and tetrahydrofuran as promising biomaterials for the applications of tissue engineering, particularly of epidermal engineering.Electronic Supplementary MaterialSupplementary material is available in the online version of this article at 10.1007/s13233-020-8109-x.

System‐of‐systems tools and techniques for the analysis of cyber‐physical systems

AbstractDynamic and real‐time adaptive configuration of Cyber‐Physical Systems (CPSs) results in increased complexity due to a variety of heterogeneous and interdependent variables and creates unique challenges. For example, (a) Emergent Behavior: How do we ensure that system constituents dynamically and adaptively collaborate to produce a consistent repeatable functionality while supporting the capability to upgrade the individual entities through technology infusion; (b) Scale: How do we ensure scalability of these systems by managing complexity; and (c) Risk Management: How do we evaluate and manage the risks associated with the connection and interdependencies of heterogenous systems. Design and development of this new generation of CPSs can be viewed through the lens of System‐of‐Systems (SoS) methodology which is designed to analyze and assess the evolving topologies created by interactions within a large complex system operating in dynamic and uncertain environment. In this paper, we propose the use of several SoS tools and techniques for the analysis and design of next‐generation CPSs. Our SoS methodologies address features such as diversity of component systems, complex hierarchical structures, dynamic and emergent behavior, and interactions between components. Therefore, they are suitable to treat some of the challenging features of CPSs. However, it is necessary to modify these methodologies to address specific aspects of CPSs. Constraints and metrics from SoS methodology, applied to the design space, will support decision on component systems and the topology of their connections, and provide a set of “good designs,” with desired characteristics.

Удосконалена методика раціонального розподілу інформації за важливістю і кількістю джерел радіомоніторингу в АСУ військами та зброєю

When designing automated systems for command and control of troops and weapons, an important role is given to the form and volume of information transmitted information. Information in the control loop comes from sensors that make up the monitoring system and continuously monitor the sources and objects of monitoring. The control and communication system of a group object of radio monitoring is a complex hierarchical structure. The number of sources that operate in the interests of providing a control system exceeds the number of available forces and means that carry out radio monitoring. There is a discrepancy in the recognition of objects and sources of radio monitoring: identification of the object of observation, the number of signs. Therefore, it is necessary to solve the multicriteria optimization problem for identifying the operating mode of radio monitoring sources for guaranteed determination of the state of the control system and communication of the group object of radio monitoring, which consists in choosing those sources whose utility is greatest. The proposed methodology for the rational distribution of information in automated control systems by troops and weapons, by selecting the most important sources of radio monitoring and rationalizing the number of gradations of radio monitoring objects to ensure a given probability of correct recognition and guaranteed determination of their condition.

Microtensile properties and failure mechanisms of cortical bone at the lamellar level

Bone features a remarkable combination of toughness and strength which originates from its complex hierarchical structure and motivates its investigation on multiple length scales. Here, in situ microtensile experiments were performed on dry ovine osteonal bone for the first time at the length scale of a single lamella. The micromechanical response was brittle and revealed larger ultimate tensile strength compared to the macroscale (factor of 2.3). Ultimate tensile strength for axial and transverse specimens was 0.35 ± 0.05 GPa and 0.13 ± 0.02 GPa, respectively. A significantly greater strength anisotropy relative to compression was observed (axial to transverse strength ratio of 2.7:1 for tension, 1.3:1 for compression). Fracture surface and transmission electron microscopic analysis suggested that this may be rationalized by a change in failure mode from fibril-matrix interfacial shearing for axial specimens to fibril-matrix debonding in the transverse direction. An improved version of the classic Hashin's composite failure model was applied to describe lamellar bone strength as a function of fibril orientation. Together with our experimental observations, the model suggests that cortical bone strength at the lamellar level is remarkably tolerant to variations of fibrils orientation of about ±30°. This study highlights the importance of investigating bone's hierarchical organization at several length scales for gaining a deeper understanding of its macroscopic fracture behavior. Statement of SignificanceUnderstanding bone deformation and failure behavior at different length scales of its hierarchical structure is fundamental for the improvement of bone fracture prevention, as well as for the development of multifunctional bio-inspired materials combining toughness and strength. The experiments reported in this study shed light on the microtensile properties of dry primary osteonal bone and establish a baseline from which to start further investigations in more physiological conditions. Microtensile specimens were stronger than their macroscopic counterparts by a factor of 2.3. Lamellar bone strength seems remarkably tolerant to variations of the sub-lamellar fibril orientation with respect to the loading direction (±30°). This study underlines the importance of studying bone on all length scales for improving our understanding of bone's macroscopic mechanical response.

Fabrication of Highly Filled Composites with an Innovative Miniaturized Spouted Bed

In nature bio-composites such as nacre show remarkable mechanical properties due to their complex hierarchical structure and high-volume fraction of its hard component. These composites are highly interesting for structural applications in different branches of industries for mechanical engineering and process technology. The aim of this work was to provide a scalable method for the production of highly filled composites by mimicking the structure of bio-composites. Therefore, composites from iron oxide (Fe2O3) and SBC-polymer (styrene-butadiene block copolymer) were fabricated by using a miniaturized spouted bed with an innovative fluidization gap design. Small iron oxide particles (25–45 μm) were fluidized in the spouted bed and coated with a polymer solution via a bottom spray nozzle. Afterwards the coated granules were hot-pressed and the mechanical properties of the obtained composites were tested. By this method composites with a bending strength of up to 6 MPa were fabricated. Although the mechanical properties of these artificial composites are still lower than those of the natural role models, it was shown that the spouted bed is a suitable technique for the fabrication of highly filled composites. For further optimization of the mechanical properties more complex and tailor-made starting materials will be used in following studies.

INSTITUTIONAL INCENTIVES FOR INCREASING PUBLIC SECTOR EFFICIENCY IN DECENTRALIZATION

In the given paper, the features of the influence of institutional incentives and power tools on the efficiency of decentralization in ensuring prosperity and in the context of economic growth are explored. The purpose of the given paper is to determine the instruments of government and to characterize the methods of using them to promote decentralization, as well as the mechanisms for financing local governments, the decentralization of information and to define their role in the application of market incentives for decentralization. To study the peculiarities of power tools and institutional incentives for decentralization, to determine the conditions for effective work of local government financing mechanisms, the benefits of information decentralization and types of market incentives, a methodology of desk research was used with analysis of the results of theoretical and applied research published in foreign literature. Secondary information has been gathered in the context of the experience of implementing reforms on decentralization of state power, the peculiarities of the institutional environment and the establishment of stimulating factors for increasing the efficiency of state power. Institutional incentives to increase the effectiveness of decentralization have a complex hierarchical structure, and their impact depends on many factors of local culture and management traditions. Decentralization of information and different market incentives may also have different effectiveness in their application. In any case, many changes are needed in the political system. In future studies, it is planned to focus on the peculiarities of decentralization in certain regions of Ukraine and to assess the state of implementation of the proposed mechanisms for funding local governments in specific circumstances.

Effect of Bone Morphogenic Protein-2-Loaded Mesoporous Strontium Substitution Calcium Silicate/Recycled Fish Gelatin 3D Cell-Laden Scaffold for Bone Tissue Engineering

Bone has a complex hierarchical structure with the capability of self-regeneration. In the case of critical-sized defects, the regeneration capabilities of normal bones are severely impaired, thus causing non-union healing of bones. Therefore, bone tissue engineering has since emerged to solve problems relating to critical-sized bone defects. Amongst the many biomaterials available on the market, calcium silicate-based (CS) cements have garnered huge interest due to their versatility and good bioactivity. In the recent decade, scientists have attempted to modify or functionalize CS cement in order to enhance the bioactivity of CS. Reports have been made that the addition of mesoporous nanoparticles onto scaffolds could enhance the bone regenerative capabilities of scaffolds. For this study, the main objective was to reuse gelatin from fish wastes and use it to combine with bone morphogenetic protein (BMP)-2 and Sr-doped CS scaffolds to create a novel BMP-2-loaded, hydrogel-based mesoporous SrCS scaffold (FGSrB) and to evaluate for its composition and mechanical strength. From this study, it was shown that such a novel scaffold could be fabricated without affecting the structural properties of FGSr. In addition, it was proven that FGSrB could be used for drug delivery to allow stable localized drug release. Such modifications were found to enhance cellular proliferation, thus leading to enhanced secretion of alkaline phosphatase and calcium. The above results showed that such a modification could be used as a potential alternative for future bone tissue engineering research.

Hierarchical patterning via dynamic sacrificial printing of stimuli-responsive hydrogels

Inspired by stimuli-tailored dynamic processes that spatiotemporally create structural and functional diversity in biology, a new hierarchical patterning strategy is proposed to induce the emergence of complex multidimensional structures via dynamic sacrificial printing of stimuli-responsive hydrogels. Using thermally responsive gelatin (Gel) and pH-responsive chitosan (Chit) as proof-of-concept materials, we demonstrate that the initially printed sacrificial material (Gel/Chit-H+ hydrogel with a single gelatin network) can be converted dynamically into non-sacrificial material (Gel/Chit-H+–Citr hydrogel with gelatin and an electrostatic citrate–chitosan dual network) under stimulus cues (citrate ions). Complex hierarchical structures and functions can be created by controlling either the printing patterns of citrate ink or the diffusion time of citrate ions into the Gel/Chit-H+ hydrogel. Specifically, mechanically anisotropic hydrogel film and cell patterning can be achieved via two-dimensional (2D) patterning; complex external and internal 3D structures can be fabricated in stimuli-responsive hydrogel and other hydrogels that are not stimuli-responsive under experimental conditions (also owing to the erasable properties of Gel/Chit-H+–Citr hydrogel) via 3D patterning; and an interconnected or segregated fluidic network can be constructed from the same initial 3D grid structure via 4D patterning. Our method is very simple, safe and generally reagentless, and the products/structures are often erasable, compatible and digestible, enabling advanced fabrication technologies (e.g. additive manufacturing) to be applied to a sustainable materials platform.

Assessment of the Financial and Investment Components of Industrial Potential

<p>Theoretical background: The need for national industrial revival requires the assessment process of the financial and investment components of industrial potential, since such process allows for the development of a further strategy of industrial development of the country, taking into account the available opportunities as well as implementing effective government controls aimed at increasing the competitiveness of the national economy.</p><p>Purpose of the article: The development of a methodological foundation for a complex economic assessment of financial and investment components of industrial potential.</p><p>Research methods: A comparative analysis was used to study methodological approaches to the economic assessment of potential, laying the groundwork for conceptual foundations of a comprehensive economic evaluation of the financial and investment components. The types of analysis used were: a system analysis – to set the system of assessment indices and indicators of financial and investment components of industrial potential; an integral assessment analysis – to determine the integral levels of the potential development for certain types of industrial activity based on standardisation of indicators reflecting the development of financial and investment components; a statistical analysis – to identify changes in the development level of the financial and investment components of potential for certain types of industrial activity; and an abstract-logical analysis to draw conclusions and formulate theoretical generalisation of the obtained results.</p><p>Main findings: Our research collected the experiences of former scientists and developed methodological bases in order to study industrial potential as a complex economic category, the development of which is conditioned by the development level of its financial and investment components. The authors’ approach to a comprehensive economic assessment of the financial and investment components of industrial potential is based on the identification of both input and output indicators. Such allocations allowed the determining of the reproductive potential of the financial and investment components as a potential opportunity to attract relevant resources, as well as implemented potential, which characterises the effectiveness of their use (the opportunity used). Next, the input indicators were further split into general indicators – which are characterised by quantitative parameters of the scope of the resources, and reflect the involvement scale – and partial indicators, which reflect the qualitative resources characteristics. The proposed integrated indicators of the development levels of financial and investment components have a complex hierarchical structure. For example, the first level generates a set of indicators that provide for a qualitative and quantitative assessment of the development state, the second level determines the integral indices in terms of individual types of indicators, while the third level is based on the potential type (reproductive and implemented). A modified Harrington’s scale was proposed to draw a conclusion on the development level achieved for the financial and investment components of industrial potential. Research was conducted using the methodology proposed, on the development levels of financial and investment components of potential for various types of industrial activity. The results showed the existence of a high level of both reproductive and implemented potential in the production of computers, electronics and optical devices, and basic pharmaceutical products, which demonstrates the technological progress in the structural industrial potential transformation. The proposed methodological approach will allow for the definition of a “critical area” in the financial and investment components development necessary for the adoption of appropriate management decisions with regard to adjusting industrial potential development strategies.</p>

Wood–Gelatin Bio-Composite Membranes with Tunable Flux

Wood is an attractive bio-resource for the production of functional materials, as it provides a complex hierarchical structure with unique properties. It is particularly promising for membrane appl...

Simultaneously enhanced strength and ductility in a metastable β-Ti alloy by stress-induced hierarchical twin structure

A novel metastable β-Ti alloy Ti-4Mo-3Cr-1Fe with high strength and high ductility was developed through controlling the alloyʼs stability and deformation mechanisms. The microstructure consists of randomly oriented β-grains containing an even distribution of athermal ω precipitates. Under tensile loading, the alloy exhibits unprecedented and comprehensive mechanical properties including a high yield strength of 870 MPa, excellent total elongation of 41% and an ultrahigh strain hardening rate of 2.5 GPa. Based on investigations of deformation microstructures, the superior mechanical properties are attributed to stress-induced formation of a complex nano-scale hierarchical twin structure which is promoted by reversion of ω precipitates.

Porous carbon frameworks with high CO2 capture capacity derived from hierarchical polyimide/zeolitic imidazolate frameworks composite aerogels

Zeolitic imidazolate frameworks (ZIF) are widely regarded as promising materials for CO2 capture and storage because of their high specific surface areas and ordered pore structures. However, ZIF are manufactured as a fine powder, and as a result it is often challenging to process them efficiently into functional materials for practical application. Therefore, the objective of this work is to demonstrate a facile direct mixing, supercritical CO2 drying, and carbonization process for preparing a novel porous carbon materials based on polyimide/ZIF (PI/ZIF) composite aerogels. An interesting finding is that the organometallic frameworks are unstable and can collapse as mixing with the polyamic acid (PAA) solution due to the strong complexation between carboxyl group in polyamic acid chains and metal ions, which shows a great effect on the microporous structure of PI/ZIF composite aerogels. Accordingly, the resultant carbon aerogels displayed a complex hierarchical porous structure, which can be altered via ZIF loading amount (up to 20 wt%) and type of ZIF used. Although the CO2 capture performance of as-prepared PI aerogels was not significantly improved via the direct addition of ZIF, subsequent carbonization resulted in dramatic enhancements at concentrations above 10 wt% of ZIF, reaching up to 50 cm3/g (2.23 mmol/g, 298 K). Overall, we report a direct production process for preparing hierarchical PI aerogels which can be further carbonized for enhanced CO2 capture performance, demonstrating their practical functionality for CO2 adsorption.