Single System Research Articles

Ethical Expertise for Gene Diagnostics and Gene Therapy Clinical Studies

Purpose of the study: to develop proposals for improving regulatory documentation on ethical expertise (EE) of gene diagnostics and gene therapy clinical studies.Materials and methods. We used general philosophical research methods, including the formal-logical, historical method, comparative method, systematic approach and axiological method. We analyzed 10 international acts, including acts of «soft law», 4 documents adopted at the level of interstate integration entities, 7 domestic normative legal acts, and a number of various doctrinal sources on the topic under consideration. In addition, we analyzed the regulatory documents for ethical committees (EC) acivities, including those from a historical perspective.Results. We formulated the concept of EE, defined the principles and main areas of EE, including the personalized medicine, and suggested the regulatory principles of EE operating.Conclusion. To improve the regulation of EE, the legal status and requirements for the activities of independent ECs should fit the scope of EE, differentially related to the area of a trial (non-interventional trials, clinical trials with a drug treatment); at the national level, independent ECs conducting EE of drug treatmemnt clinical trials should be institutionalized into a single system; to improve the activities of independent ECs in the field of clinical testing, the development of a special normative regulation is required.

Solubility evaluation of palm-based Mono-diacylglycerols (MDAGs) in food grade solvent (hexane, ethanol, acetone, water) using QSPR model approach

Mono-diacylglycerols (MDAGs) are emulsifiers widely used in the food industry. MDAGs based on refined bleached deodorized palm stearin (RBDPS) have not been widely developed. MDAGs have been synthesized using glicerolysis between RBDPS and glycerols. Due to their low solubility in food-grade solvents (hexane, ethanol, acetone, and water), it has been difficult to purify or fractionate MDAGs only by a simple method. This research attempted to develop a model of MDAGs solubility in food-grade solvents and understand the parameters that influence the solubility of MDAGs in food-grade solvents. The process used a combination of experimental data collection and quantitative structure–property relationship (QSPR) models. The QSPR model for MDAGs solubility in a single and binary solvent demonstrated that the descriptors of Δ dipole moment (Δµ), E HOMO, E LUMO, electronic energy, gap energy HOMO-LUMO (ΔE1, ΔE2) softness (S), electrophilicity index (ω), and electron transfer (ΔN) have a significant impact in determining the solubility of MDAGs. Both the single and the binary solvents solubility models can give satisfactory prediction results: the square of the correlation coefficient (R2pred) was 0.933 and 0.948, and the root-mean-square error (RMSE) was 0.075 and 0.031, respectively, for the whole data set. In addition, this paper provided a new and effective method for predicting the solubility of MDAGs in single and binary food-grade solvent systems.

Removal of Methyl Violet 2B and Direct Black 22 from Single and Binary System Using a Magnetic Zeolite/MgO/Starch/Fe3O4 Nanocomposite

This study focuses on the preparation and characterization of magnetic zeolite (FSM-Zeo) using starch, magnesium oxide, and Fe3O4. Various analyses, including BET, FTIR, SEM, EDS, XRD, Zeta potential, and VSM, were conducted to assess the properties of FSM-Zeo. The adsorption capacity of FSM-Zeo was investigated for methyl violet (MV-2B) and direct black 22 (DB-22) in both single and binary dye solutions. Key parameters such as adsorbent amount, initial dye concentration, contact time, temperature, initial pH, and ionic strength were examined in the single system. Kinetic and isotherm studies revealed that DB-22 and MV-2B adsorption followed the pseudo-second-order model. Moreover, Freundlich and Langmuir models were confirmed for MV-2B and DB-22 adsorption on FSM-Zeo, respectively. In the binary system, the presence of MV-2B enhanced the adsorption of DB-22, resulting in higher removal compared to the single dye solution. A synergistic effect was observed due to the interaction between DB-22 and MV-2B, promoting the adsorption of DB-22 on FSM-Zeo.

Synergistic Effect of Betaines and Dialkyl Chain Anionic Surfactants on Interfacial Arrangement: A Molecular Dynamics Simulation Study.

Mixed systems of betaines and anionic surfactants can have a significant synergistic effect and greatly reduce the interfacial tension (IFT), which has attracted an extensive amount of attention. However, this synergistic effect requires an anionic surfactant and betaine molecular size matching, which limits the scope of its application. In this work, we studied three mixed systems of sodium dialkyl sulfosuccinate (AOT) and betaines with different sizes by molecular dynamics simulation and an IFT experiment and explored the interfacial behavior and synergistic mechanism of AOT in single and mixed systems. The hydrophobic tail chain center angle, average rising height of carbon atoms, stretch degree and distance between the terminal carbon atoms of AOT, and tilt angles of betaine were calculated and analyzed in detail. Simulation results showed that the hydrophobic tail chain center angle of AOT in the single system was smaller, and it tended to extend into the oil phase. After being mixed with different betaines, AOT can adjust its size according to the interfacial vacancies of different betaine systems by changing the alkyl chain orientation and forming tighter interfacial films. The IFT experiment showed that betaine/AOT mixed systems achieved a lower IFT value compared with that of the single system, indicating that AOT showed a synergistic effect with betaines with different structures. This study will be importantly instructively significant for the design and research of betaine mixed systems in crude oil exploitation.

Ultrasensitive Solvatochirochromism of Single Benzene Chromophores.

Solvents influence the structure, aggregation and folding behaviors of solvatochromic compounds. Ultrasensitive solvent mediated chiroptical response is conducive to the fabrication of molecular platform for sensing and recognition, which however, remains great challenges in conceptual or applicable design. Here we report a cysteine-based single benzene chromophore system that shows ultrasensitivity to solvents. Compared to the ratiometrically responsive systems, the chiroptical activities could be triggered or inverted depending on the substituents of chiral entities with an ultralow solvent volume fraction (<1 vol %). One drop of dipolar solvents shall significantly induce the emergence or inversion of chiroptical signals in bulky phases. Based on the experimental and computational studies, the ultrasensitivity is contributed to the intimate interplay between solvents and chiral compounds that anchors the specific chiral conformation. It illustrates that structurally simple organic compounds without aggregation or folding behaviors possess pronounced solvatochiroptical properties, which sheds light on the next-generation of chiroptical sensors and switches.

Calculation method of carbon flow distribution in load-intensive regional energy centers

With the development of the economy, people’s demand for green energy has increased significantly. However, the traditional single fossil energy supply system cannot meet the needs of low-carbon. Therefore, this study employs energy hub to establish a multi-energy flow network that enables the integration of carbon flow within the network. Additionally, by utilizing the multi-energy flow trend, a carbon flow tracking method is adopted to achieve real-time carbon flow calculation. Results show that this network calculates the electricity cost of 20043 yuan, gas cost of 67253 yuan, and carbon emission cost of 3152 yuan. Compared with the traditional energy flow system, gas cost is reduced by 4.3% and 1.7%, electricity cost by 21.3% and 15.0%, and carbon emission cost by 8.7% and 6.6%. The two-way sharing carbon flow calculation model calculates that the user side and power supply side of the node each bear half of the network loss, proving two-way sharing effectiveness. Test results on IEEE5 machine 14-node system show that the calculation method can accurately find high-emission and low-emission areas, making the carbon emission allocation between power generation and user more fair and reasonable. This research can effectively reduce emissions cost, accurately calculate emissions flow in real time, and facilitate reasonable emission reduction planning.

Albumin promoter-driven FlpO expression induces efficient genetic recombination in mouse liver.

Tissue-specific gene manipulations are widely used in genetically engineered mouse models. A single recombinase system, such as the one using Alb-Cre, has been commonly used for liver-specific genetic manipulations. However, most diseases are complex, involving multiple genetic changes and various cell types. A dual recombinase system is required for conditionally modifying different genes sequentially in the same cell or inducing genetic changes in different cell types within the same organism. A FlpO cDNA was inserted between the last exon and 3'-UTR of the mouse albumin gene in a bacterial artificial chromosome (BAC-Alb-FlpO). The founders were crossed with various reporter mice to examine the efficiency of recombination. Liver cancer tumorigenesis was investigated by crossing the FlpO mice with FSF-KrasG12D mice and p53frt mice (KPF mice). BAC-Alb-FlpO mice exhibited highly efficient recombination capability in both hepatocytes and intrahepatic cholangiocytes. No recombination was observed in the duodenum and pancreatic cells. BAC-Alb-FlpO-mediated liver-specific expression of mutant KrasG12D and conditional deletion of p53 gene caused the development of liver cancer. Remarkably, liver cancer in these KPF mice manifested a distinctive mixed hepatocellular carcinoma and cholangiocarcinoma phenotype. A highly efficient and liver-specific BAC-Alb-FlpO mouse model was developed. In combination with other Cre lines, different genes can be manipulated sequentially in the same cell, or distinct genetic changes can be induced in different cell types of the same organism.NEW & NOTEWORTHY A liver-specific Alb-FlpO mouse line was generated. By coupling it with other existing CreERT or Cre lines, the dual recombinase approach can enable sequential gene modifications within the same cell or across various cell types in an organism for liver research through temporal and spatial gene manipulations.

Fabrication, Design, and Analysis of Dual Axis Solar Tracking System

Energy crisis is one of the prime issues in the third world developing country like Bangladesh. There is an enormous gap between generation and demand of electrical energy. Nearly 50% of the population of the country is extremely isolated from this blessing. Renewable energy is the only answer to solve this issue. Solar energy is one of the most effective resources of renewable energy which could play a significant role in solving this crisis. This research presents a performance analysis of the dual axis solar tracking system using Arduino. The main objective of this research is whether a static solar panel is better than a solar tracker or not. This work is divided into two parts, hardware, and software system. In the hardware part, four light dependent resistors (LDR) is used to detect the utmost light source from the sun. Two servo motors conjointly used to move the solar panel to maximum light source location perceived by the LDRs. In the software part, the code is written by using C programming language and has targeted to the Arduino UNO controller. The outcome of the solar tracker system has analyzed and compared with the fixed or static solar panel found better performance in terms of voltage, current and power. Therefore, the solar tracker has proved more practical for capturing the maximum sunlight supply for star harvesting applications. The result showed dual- axis solar tracking system produced extra 10.53-watt power compared with fixed and single axis solar tracking system. Key Words: Solar Pannel, Servo Motor, LDR

PRogramAR: Augmented Reality End-User Robot Programming

The field of end-user robot programming seeks to develop methods that empower non-expert programmers to task and modify robot operations. In doing so, researchers may enhance robot flexibility and broaden the scope of robot deployments into the real world. We introduce PRogramAR (Programming Robots using Augmented Reality), a novel end-user robot programming system that combines the intuitive visual feedback of augmented reality (AR) with the simplistic and responsive paradigm of trigger-action programming (TAP) to facilitate human-robot collaboration. Through PRogramAR, users are able to rapidly author task rules and desired reactive robot behaviors, while specifying task constraints and observing program feedback contextualized directly in the real world. PRogramAR provides feedback by simulating the robot’s intended behavior and providing instant evaluation of TAP rule executability to help end users better understand and debug their programs during development. In a system validation, 17 end users ranging from ages 18 to 83 used PRogramAR to program a robot to assist them in completing three collaborative tasks. Our results demonstrate how merging the benefits of AR and TAP using elements from prior robot programming research into a single novel system can successfully enhance the robot programming process for non-expert users.

An Exhaustive Examination of the Motor System’s Reliability in Electric Vehicles

Due to their unique zero carbon emission feature, electric vehicles (EVs) have garnered increasing interest in recent years. However, concerns persist regarding their reliability, particularly concerning critical components. Efforts have been made to assess the reliability of drive motors in EVs. Yet, given the integration of drive motors and motor controllers as a single system in EVs, a combined assessment is essential for a more accurate reliability prediction. Additionally, considering the multiple components within both drive motors and motor controllers, their structure, type, and characteristics may influence the overall reliability of the motor system, a factor overlooked in previous research. To bridge this knowledge gap, this study investigates the reliability of the entire motor system in pure electric vans, encompassing both drive motors and motor controllers. The research begins with predicting the theoretical failure rates of subassemblies and components within the drive motor and motor controller. Subsequently, based on these predictions, the reliability of the entire motor system is assessed. The findings highlight vulnerable subassemblies and components within the motor system, shedding light on potential shortcomings in existing reliability research. These new insights are deemed crucial for informing future reliability design and maintenance practices for pure electric vans. This study undertakes an exhaustive investigation into the reliability of the motor system in EVs. As EVs gain prominence for their environmental benefits and increasing market share, concerns regarding the reliability of critical components, such as the drive motor and associated control systems, become paramount. While prior research has addressed component-level reliability, this study takes a holistic approach by assessing the entire motor system. Through theoretical modeling and empirical analysis, the study predicts failure rates of subassemblies and components within the drive motor and control systems, culminating in an evaluation of the overall motor system reliability. By uncovering vulnerabilities and potential areas for improvement, this research offers valuable insights to advance the design, development, and maintenance of reliable electric vehicles.

The Need to Harmonize the Labor Legislation of Pharmaceutical Workers of the Member States of the Eurasian Economic Union (EAEU)

The paper is devoted to topical issues of legal regulation of the work of pharmaceutical workers both at the level of international legal acts of the Eurasian Economic Union (EAEU) and at the level of national legislation of the member states. These problems include the lack of a uniform integrated approach to the regulation of the work of pharmaceutical workers in international legal acts and its fragmentation. This leads to a decrease in the effectiveness of legal regulation of these categories of subjects of labor law. The situation gives rise to two dialectically interrelated trends at the EAEU level. On the one hand, international legal acts on the drug market of this organization contain norms that regulate the work of pharmaceutical workers. On the other hand, these norms do not cover all aspects of the work of pharmaceutical workers. The solution to this problem is seen in changing the international legal acts of the EAEU on the drug market by stipulating the norms regulating the work of pharmaceutical workers, considered in a single system and in close relationship with pharmaceutical activities. This is possible through the analysis, and in the future, the use of positive legal experience in regulating the labor of pharmaceutical workers in the EAEU countries to develop separate sections of the international legal acts of the EAEU in the field of regulation of the pharmaceutical market (in the form of appendices thereto).

Magnetic irregularity measurement and signal processing of permanent magnet guideway for superconducting pinning maglev train

Superconducting pinning maglev train, with the advantages of heavy self-stable levitation and super-low resistance, is expected to become a high-speed transit in the future. With the increase in speed, the more will the irregularity of the PMG (permanent magnet guideway) affects the safety and comfort of the superconducting pinning maglev train. This paper is based on the PMG of the test line for the first high-speed superconducting pinning maglev engineering prototype train in China, to measure and study the magnetic irregularity of the PMG and its characteristics. Experiments were designed to measure the irregularity with a single Dewar maglev system, which can obtain the equivalent geometric irregularity directly acting on the maglev unit of the vehicle. Firstly, the frequency response function is developed based on previous studies, which can transform the response signal of the Dewar into the irregularity signal of the PMG. Secondly, the velocity and position are measured by image recognition of ground markers. Then, the dynamic signal of the Dewar maglev system moving along the PMG is gained and conversed into equivalent geometric irregularities by the frequency response function. Finally, an equivalent geometric irregularity PSD (power spectral density) function is formed, and it can generate the geometrically random track irregularity for vehicle dynamic simulations. The dynamic simulation result suggests that the superconducting pinning maglev train has the potential for smooth operation at high-speed under the excitation of the current PMG. The studies of this paper can help to understand the irregularity of the PMG further, and the gained PSD function can provide a general reference for the dynamic study of the superconducting pinning maglev train.

Passive Visual Odometry of Mobile Transport Robots in Production Areas Using Anchor Points

The article considers the problem of determining the orientation of mobile transport robots, which are now actively used in almost all areas of industry. They make it possible to intensify production, free personnel from performing routine operations, and exclude the influence of the human factor from work. Based on the analysis of various variants of active orientation methods involving the use of binocular video systems installed on the vehicles themselves, it is proposed to use a passive orientation detection system. It includes a single stationary monocular video system, the replacement of onboard video systems on mobile robots with simple radiation sensors, as well as the use of anchor points in the area of their movement. The order of choice of anchor points in solving the problem of orientation of a mobile transport robot using a monocular video system, in particular for a rectangular interior space, is considered. Calculation formulas for determining the coordinates of the sensor from the pixel coordinates of its image obtained from a monocular video camera are determined. The general sequence of actions for determining the orientation of a mobile robotic platform is also considered. Unlike active systems, this method makes it possible to significantly simplify the hardware, significantly facilitate the analysis of the current position of the mobile robot and thereby reduce the computational complexity of calculations due to the fact that there is no need to use a complex mathematical apparatus. It is being replaced by simpler two-dimensional geometric calculations. This approach, due to the unified management, makes it possible to effectively coordinate the actions of a group of mobile transport robots when they are used together, greatly simplifies the solution of a number of tasks for optimizing the intra-shop movement of mobile vehicles.

Abstract A053: Understanding geospatial relationships in ovarian cancer risk

Abstract To examine the geographic distribution of ovarian cancer cases in the New England area and identify potential case clusters. Methods: This was a case-control study utilizing 1580 ovarian cancer patients from a single healthcare system (MGB). Using electronic health record (EHR) review, patient primary addresses were geocoded. To account for spatial distribution confounded by access to the MGB health system, 1750 patients from the MGB biobank system were geocoded as controls. Generalized additive models were used to determine the spatial patterning of cases and controls, controlled for age and race. Geospatial analysis was performed using ArcGIS software and R. Results: 3325 patients (1576 ovarian cancer patients, 1749 biobank controls) were successfully geocoded. Distribution of ovarian cancer cases and biobank patient controls were similar (average nearest neighbor distance 6337m vs 5623 m). Among the cohort of patients in New England (defined as MA, ME, NH, VT, RI, CT), there were 1476 ovarian cancer patients and 1663 biobank control patients. Use of a generalized additive model demonstrated higher incidence of ovarian cancer in Western CT, western MA, VT, and southern ME. These data are similar to SEER reported county-level incidence of late-stage ovarian cancer. Conclusions: Understanding the geospatial distribution of ovarian cancer cases can highlight potential clusters of higher incidences of disease. Causal relationships have yet to be established and require future investigation, but these data suggest spatially patterned exposures are worth examination. Citation Format: Victoria Wang, Jaime Hart, Kevin Elias. Understanding geospatial relationships in ovarian cancer risk [abstract]. In: Proceedings of the AACR Special Conference on Ovarian Cancer; 2023 Oct 5-7; Boston, Massachusetts. Philadelphia (PA): AACR; Cancer Res 2024;84(5 Suppl_2):Abstract nr A053.

The role of macroinvertebrate taxonomic resolution in bioassessment of urban streams: A case study from the City of Lodz, Poland

Benthic macroinvertebrates were sampled at 28 sites situated on ten urban streams (Łódź, Poland) representative of a wide range of anthropogenic modifications of water chemistry and bed structure. A total of 5,043 individuals, comprising 121 species belonging to 37 families and 15 orders, were collected. Diptera (35.8 %) and Ephemeroptera (31.8 %) were dominant.The studied sites were grouped into clusters based on separately-analyzed environmental parameters, various levels of taxonomic diversity, and bioassessment variables. All analyses demonstrated similar trends of anthropogenic modification, intensifying concentrically from the suburbs towards the city centre. The first cluster included the upper section of streams; less polluted, richer in ecotone zones and natural stream bed substrate. The second cluster comprised streams demonstrating the influence of moderate human pressure. The third cluster included streams flowing through the city center in concreted beds and which were connected to a combined sewage system in which sewage and rain water are transported through a single canal system and enters the nearest stream. Modification of stream beds was significantly negatively correlated with the number of species, families and orders, but not with total abundance.The number of species, the number of families and the number of orders were highly mutually correlated. Moreover, they were similarly correlated with biodiversity and biotic indices, which are used to assess the ecological status of the aquatic environment. Hence, different levels of taxonomic identification demonstrate similar effectiveness in assessment, i.e. higher taxa of aquatic macroinvertebrates may be suitable for simplified ecological monitoring of urban watercourses.

Sagittal Angulation and the Treatment of Geriatric Femoral Neck Fractures: Time to Update our Classification Systems.

Inconsistent outcomes have been reported for percutaneous fixation of Garden I/II femoral neck fractures in geriatric patients. It was hypothesized that accounting for variable follow-up would better estimate the failure rate of percutaneous fixation with and without significant sagittal angulation. Retrospective. Single academic healthcare system. Patients ≥50 years of age treated with percutaneous screw fixation of Garden I/II (OTA/AO B1.1/B1.2) femoral neck fractures from 2010 to 2020 were identified. Pathologic fractures and open approaches were excluded. Sagittal angulation was measured using a previously described method. 11 Treatment failure was defined as early fixation failure (within 6 weeks), nonunion, and/or avascular necrosis. Potential associations between treatment failure and patient, injury, and treatment variables were assessed. Cox proportional hazard analysis accounted for variable follow-up when assessing for event-free survival. Of the 240 fractures that met inclusion criteria, there were 20 treatment failures (8%) and 33 fractures with sagittal angulation ≥20 degrees on lateral radiographs (14%). Failure-free survival at 2 years was 91% for patients with <20 degrees of posterior angulation and 52% for patients with ≥20 degrees of posterior angulation ( P < 0.0001). The hazard ratio, which incorporates variable follow-up, for failure with ≥20 degrees of posterior angulation was 6.36 ( P < 0.0001). No other factors were associated with treatment failure. Significant posterior angulation (≥20 degrees) of Garden I/II femoral neck fractures is associated with a high failure rate after screw fixation. The authors suggest characterizing fractures with ≥20 degrees of sagittal angulation as Garden III fractures to better support surgical decision making. Prognostic Level III. See Instructions for Authors for a complete description of levels of evidence.

REVISÃO INTEGRATIVA E SISTEMÁTICA SOBRE PARCERIAS PÚBLICO-PRIVADAS NA ADMINISTRAÇÃO PÚBLICA

Public Administration is the set of activities undertaken by the State with the objective of promoting the common good, through the use of authority powers and the implementation of public policies, programs and services. Public Administration management in Brazil faces a series of challenges that compromise the efficiency and effectiveness in the use of public resources, including problems such as excessive bureaucracy, the lack of strategic planning, corrupt practices and the phenomenon of clientelism. Therefore, the present study, undertaken an Integrative Systematic Review (RSI), had the purpose of examining articles related to public-private partnerships in public administration, which were published in the Scientific Electronic Library Online (SCIELO) database in the period time between 2012 and 2022. The main findings were that the most published articles are mostly related to health and education, which together represent a total of 15 articles. The presence of literature reviews on the topic was observed; public-private partnerships in the Brazilian public sectors and the main themes found in relation to this topic include: studies presented a single health system, government regulation, education policies, urban mobility, educational governance, health service reforms/health policy.

Balancing risks and rewards of alternate strategies in the seaward extent, duration and timing of fjord use in contemporary anadromy of brown trout (Salmo trutta)

BackgroundAnadromy comprises a successful life-cycle adaptation for salmonids, with marine migration providing improved feeding opportunities and thus improved growth. These rewards are balanced against costs from increased energy expenditure and mortality risk. Anthropogenic-induced environmental changes that reduce benefits and/or increase costs of migration e.g., aquaculture and hydropower, may therefore result in adaptations disfavouring anadromy. We tagged brown trout (Salmo trutta) smolts (N = 175) and veteran migrants (N = 342), from five adjacent riverine populations located in Sognefjorden, the longest Norwegian fjord-system supporting anadromous brown trout populations (209 km). Over four years, 138 acoustic telemetry receivers were deployed to track migrations of tagged individuals from freshwater and throughout Sognefjorden. Detected movements were used to fit migration models and multi-state mark-recapture models of survival and movement for each life-stage. Seaward migration distance was modelled to examine the fitness consequences from alternate migration strategies, with these models used to simulate the extent of fjord-use by individuals and accompanying growth, fecundity and survival consequences. We compared these findings with mark-recapture data collected prior to aquaculture and hydropower development.ResultsThe telemetry data revealed that the outermost-fjord region was utilised by all populations albeit by few individuals. However, historical recaptures were located at a greater distance from the river mouth (87.7 ± 70.3 km), when compared to maximum migration distances of present-day counterparts (58.6 ± 54.9 km). River of origin influenced observed migratory behaviour and differential survival was estimated for each population and life-stage. The simulations based on telemetry-data models revealed a 30% and 23% difference in survival among populations for smolts and veteran migrants, respectively. At the individual-level, a long-distance migration strategy was rewarded with enhanced fecundity. However, the main contribution to population-level fecundity was overwhelmingly derived from middle-distance migrants, due to higher mortality rates and limited numbers of long-distant migrants.ConclusionsWe conclude that present-day anadromy is precarious, but potential risk varies considerably between life-stages and populations, even within a single fjord system. Our findings suggest that selection for extended migration is under pressure, we therefore stress the importance of monitoring and management actions to secure genetic variation pertinent to preserve fitness gains of anadromy.

Experimental investigation on the self-healing properties of ester-exchanged vitrimeric CFRP laminate with microchannels

Epoxy vitrimer theoretically achieves an unlimited healing cycle drawing support from dynamic molecular chains. The healing conditions required for microvascular systems are variable and flexible. Current research has often focused on a single healing system, further exploration is needed for a dual healing system that combines the advantages of both. In this study, the effects of curing agent and catalyst content on the performances of vitrimer, as well as the healing parameters on the healing efficiency were studied. And then the vitrimeric CFRP (vCFRP) laminates with microchannels were prepared, and the three-point bending tests were implemented to characterize the healing efficiency of CFRP with a single and dual healing system. The results indicated that the cured vitrimer exhibited the best comprehensive performance when the molar ratio of reactants was 1:1:0.07. The healing temperature had the greatest impact on the healing efficiency of vitrimer, followed by the catalyst content and the healing pressure. The two healing systems could improve the mechanical properties of laminates, especially the healing efficiency of CFRP with dual healing system reached 134.5 %. The healing agent in the microchannels could heal micro-damage, and the healability of the vitrimer could still be utilized after the healing agent was exhausted.

Polyoxometalate‐Based Frameworks: Construction Strategies and Photocatalytic Applications

Polyoxometalate‐based frameworks, as a kind of material constructed by polyoxometalates (POMs), metal ions or clusters, organic ligands, are combined both the advantages of oxygen‐rich POMs and porous metal‐organic frameworks (MOFs) within one single system. This integration greatly expands their potential applications compared to the individual POMs or MOFs. Particularly for photocatalysis, the narrow light absorption range of the typical POMs units in the ultraviolet region hinders their extensive uses as visible‐light‐driven photocatalysts. However, the incorporation of photoactive units into POMs‐based frameworks can be considered as an effective approach to overcome this limitation. In this paper, we review selected examples of recent progress based on the POM‐based frameworks along with their construction strategies and applications in various areas of photocatalysis, mainly including water splitting, CO2 reduction, organic synthesis and also the selective coupling reactions.