Engineering Development Research Articles

Overview of research on intelligent swarm munitions

This article started with an overview of the current technological status and engineering developments in the field of swarm munitions. It first introduced swarm behaviors and related swarm algorithms, and then provided a comprehensive summary of the research progress in the field of swarm munitions from four aspects: Collaborative perception and detection, collaborative positioning and navigation, task allocation for swarms, and path planning for swarms. In summary, future developments in collaborative perception, planning, positioning, navigation, and decision-making for swarm munitions will trend towards intelligence, adaptability, and collaboration. It can enable swarm munitions to be better adapted to complex and dynamic battlefields, improving operational effectiveness and mission capabilities.

Mass spectrometry-based structure-specific N-glycoproteomics and biomedical applications.

N-linked glycosylation is a common posttranslational modification of proteins that results in macroheterogeneity of the modification site. However, unlike simpler modifications, N-glycosylation introduces an additional layer of complexity with tens of thousands of possible structures arising from various dimensions, including different monosaccharide compositions, sequence structures, linking structures, isomerism, and three-dimensional conformations. This results in additional microheterogeneity of the modification site of N-glycosylation, i.e., the same N-glycosylation site can be modified with different glycans with a certain stoichiometric ratio. N-glycosylation regulates the structure and function of N-glycoproteins in a site- and structure-specific manner, and differential expression of N-glycosylation under disease conditions needs to be characterized through site- and structure-specific quantitative analysis. Numerous advanced methods ranging from sample preparation to mass spectrum analysis have been developed to distinguish N-glycan structures. Chemical derivatization of monosaccharides, online liquid chromatography separation and ion mobility spectrometry enable the physical differentiation of samples. Tandem mass spectrometry further analyzes the macro/microheterogeneity of intact N-glycopeptides through the analysis of fragment ions. Moreover, the development of search engines and AI-based software has enhanced our understanding of the dissociation patterns of intact N-glycopeptides and the clinical significance of differentially expressed intact N-glycopeptides. With the help of these modern methods, structure-specific N-glycoproteomics has become an important tool with extensive applications in the biomedical field.

Minimally Invasive Surgery for Hirschsprung Disease: Current Practices and Future Directions.

Hirschsprung disease (HD) is a congenital disorder characterized by the absence of ganglion cells in the distal colon and rectum, leading to functional obstruction and severe constipation. Over the past decades, the surgical management of HD has significantly evolved, with minimally invasive surgery (MIS) techniques revolutionizing treatment approaches. This review explores recent innovations in MIS for HD, focusing on laparoscopic, transanal endorectal pull-through (TERPT), and robotic-assisted techniques. These approaches offer numerous advantages over traditional open procedures, including reduced surgical trauma, improved cosmesis, faster recovery times, and potentially lower complication rates. Laparoscopic surgery has become widely adopted, providing excellent visualization and precise dissection. TERPT has gained popularity for short-segment disease, offering a completely transanal approach with minimal scarring. Robotic-assisted surgery represents the cutting edge, enhancing surgical precision and dexterity. The review also examines emerging technologies and future directions, such as advanced imaging techniques, artificial intelligence applications, and potential developments in tissue engineering. While MIS techniques have shown promising outcomes, challenges remain in standardizing approaches, addressing long-segment disease, and optimizing long-term functional results. The future of HD surgery lies in personalized approaches that integrate genetic and molecular profiling with advanced surgical technologies. As the field continues to evolve, comprehensive long-term studies and efforts to improve access to specialized care will be crucial to further enhancing outcomes for patients with HD.

GO/Cu Nanosheet-Integrated Hydrogel Platform as a Bioactive and Biocompatible Scaffold for Enhanced Calvarial Bone Regeneration.

The treatment of craniofacial bone defects caused by trauma, tumors, and infectious and degenerative diseases is a significant issue in current clinical practice. Following the rapid development of bone tissue engineering (BTE) in the last decade, bioactive scaffolds coupled with multifunctional properties are in high demand with regard to effective therapy for bone defects. Herein, an innovative bone scaffold consisting of GO/Cu nanoderivatives and GelMA-based organic-inorganic hybrids was reported for repairing full-thickness calvarial bone defect. In this study, motivated by the versatile biological functions of nanomaterials and synthetic hydrogels, copper nanoparticle (CuNP)-decorated graphene oxide (GO) nanosheets (GO/Cu) were combined with methacrylated gelatin (GelMA)-based organic-inorganic hybrids to construct porous bone scaffolds that mimic the extracellular matrix (ECM) of bone tissues by photocrosslinking. The material characterizations, in vitro cytocompatibility, macrophage polarization and osteogenesis of the biohybrid hydrogel scaffolds were investigated, and two different animal models (BALB/c mice and SD rats) were established to further confirm the in vivo neovascularization, macrophage recruitment, biocompatibility, biosafety and bone regenerative potential. We found that GO/Cu-functionalized GelMA/β-TCP hydrogel scaffolds exhibited evidently promoted osteogenic activities, M2 type macrophage polarization, increased secretion of anti-inflammatory factors and excellent cytocompatibility, with favorable surface characteristics and sustainable release of Cu2+. Additionally, improved neovascularization, macrophage recruitment and tissue integration were found in mice implanted with the bioactive hydrogels. More importantly, the observations of microCT reconstruction and histological analysis in a calvarial bone defect model in rats treated with GO/Cu-incorporated hydrogel scaffolds demonstrated significantly increased bone morphometric values and newly formed bone tissues, indicating accelerated bone healing. Taken together, this BTE-based bone repair strategy provides a promising and feasible method for constructing multifunctional GO/Cu nanocomposite-incorporated biohybrid hydrogel scaffolds with facilitated osteogenesis, angiogenesis and immunoregulation in one system, with the optimization of material properties and biosafety, it thereby demonstrates great application potential for correcting craniofacial bone defects in future clinical scenarios.

A proposed semantic keywords search engine for Indonesian Qur’an translation based on word embedding

Obtaining relevant information from the Holy Qur’an can be really challenging for people who cannot speak Arabic, such as the Indonesian people. One technology implementation which is commonly used to tackle this problem is to develop a search engine application for Al-Qur’an verses. This paper proposes a search engine based on semantic representation keywords for the Indonesian translation of the Al-Qur’an which consists of 3 phases i.e., data preparation, document representation, and search engine development. In the first stage, the Al-Qur’an dataset was built using the official translation of the Al-Qur’an from the Ministry of Religion and then enriched with the Wikipedia corpus. The second phase is document representation which produces feature vectors by utilizing the Word2Vec algorithm. Finally, the development of a search engine that can find the most relevant verses by calculating the cosine similarity between the document and the keywords. It was found that the proposed search engine succeeded in exceeding the performance of ordinary search engines by finding wider information due to the use of semantic keywords. Apart from that, the proposed search engine succeeded in maintaining the relevance of search results by achieving precision and recall levels of 98.7% and 97.3% respectively.

Fibre-reinforced geopolymer (FRG) cemented aeolian sand flexural properties and microproduct evolutionary processes

To reveal the flexural behaviour and microproduct evolution mechanism of FRG cemented aeolian sand, four factors, namely, sodium hydroxide dosage, water-solid ratio, fibre dosage, and fibre length, were classified into mutually independent levels and combined to form a set of test matrices for the design of orthogonal tests. Using DIC digital scattering technology to analyze the evolutionary process of specimen ring-breaking and employing scanning electron microscopy to explore the polymerization product micro-morphology, evolutionary process, pore defects, and analyze the fiber endowment morphology and the destruction mode; the use of EDS spectroscopy, X-ray diffraction, Fourier IR spectroscopy, and other technical means to analyze the polymerization product chemical composition, elemental distribution, and evolutionary characteristics. The results of the study show that the 28-day flexural performance of FRG cemented wind-blown sand as a filling material is significantly affected by various factors in the following order of magnitude: sodium hydroxide dosage > water-solid ratio > fibre dosage > fibre length. The optimal combination from the local test is: sodium hydroxide dosage of 1.4 %, the water-solid ratio of 0.32, the fibre dosage of 0.5 %, and the fibre length of 12 mm. With the increase in load, the value of the displacement field increases continuously, indicating a greater degree of specimen damage. As the reaction proceeds, the polymerization product's morphology evolves from rod-like to flaky, ultimately stabilizing into a network structure. The main elements in the product include C, O, Si, Al, and Ca, indicating that the polymerization product is a C-(A)-S-H gel. A reasonable distribution of discrete ductile fibers can play a positive role inside the specimen, acting as a bridge. The damage behavior under bridging can be divided into fiber debonding, producing slippage behavior, and fiber damage, leading to fracture behavior. The results of the study provide a scientific basis for the design, preparation, and application of solid waste filling materials, thereby promoting the development of materials science and engineering.

The reduction in relative brain size in the domesticated dog is not an evolutionary singularity among the canids.

Domestication has long been considered the most powerful evolutionary engine behind dramatic reductions in brain size in several taxa, and the dog (Canis familiaris) is considered as a typical example that shows a substantial decrease in brain size relative to its ancestor, the grey wolf (Canis lupus). However, to make the case for exceptional evolution of reduced brain size under domestication requires an interspecific approach in a phylogenetic context that can quantify the extent by which domestication reduces brain size in comparison to closely related non-domesticated species responding to different selection factors in the wild. Here, we used a phylogenetic method to identify evolutionary singularities to test if the domesticated dog stands out in terms of relative brain size from other species of canids. We found that the dog does not present unambiguous signature of evolutionary singularity with regard to its small brain size, as the results were sensitive to the considerations about the ancestral trait values upon domestication. However, we obtained strong evidence for the hibernating common raccoon dog (Nyctereutes procyonoides) being an evolutionary outlier for its brain size. Therefore, domestication is not necessarily an exceptional case concerning evolutionary reductions in brain size in an interspecific perspective.

Technological innovations in agricultural bioenergy production: A concept paper on future pathways

This review paper explores the current state, emerging trends, and future pathways of technological innovation in agricultural bioenergy production. It examines key developments in biomass conversion technologies, genetic engineering, precision farming, and biorefineries, highlighting their potential applications, benefits, and challenges. The importance of continued research and innovation in advancing bioenergy technologies is underscored, emphasizing their potential contributions to sustainability, energy security, and rural development. By harnessing renewable biomass resources and leveraging cutting-edge technologies, agricultural bioenergy holds promise as a sustainable and renewable energy solution. This paper calls for collaborative efforts and informed decision-making to realize the full potential of bioenergy in mitigating climate change, promoting environmental stewardship, and enhancing energy resilience.'

Experimental study on impact performance of seawater sea-sand concrete with recycled aggregates

On islands distant from the mainland, obtaining raw materials for concrete production is often more challenging. To achieve sustainable development in island reef engineering, using discarded marine concrete and coral waste generated during island construction as recycled aggregates are of considerable significance. The preparation of Recycled Coral Aggregate Concrete (RCAC) for island reef engineering thus holds substantial importance. In this study, RCAC and Natural Aggregate Concrete (NAC), both designed with a compressive strength of C60, were prepared. Initially, the fundamental physical properties of the recycled coarse aggregate, such as apparent density, water absorption, and crushing index, were determined. Subsequently, a comparative analysis of the quasi-static mechanical properties of RCAC with varying proportions of recycled coral coarse aggregate (RCCA) was conducted. Furthermore, the impact compression mechanical properties of different RCAC specimens under various strain rates were examined using the Ф100mm Split Hopkinson Pressure Bar (SHPB) apparatus. The microstructure and long-term drying shrinkage performance of RCAC were also analyzed using Scanning Electron Microscopy (SEM) and a drying shrinkage apparatus. The finding indicated that the 28-day compressive strength of RCAC specimens with 100% coarse aggregate replacement reached a maximum of 62.4 MPa. The quasi-static compressive strength of RCAC specimens with 50% and 100% RCCA replacement was only 11.5% and 14.2% lower than that of NAC, respectively. Under impact loading, the dynamic compressive strength of RCAC specimens increased with the strain rate, with peak stress exhibiting an approximately linear relationship with the strain rate. The energy dissipation of RCAC specimens generally occurred in three stages, with the reflected and absorbed energies of the specimens increasing linearly with strain rate. At the same strain rate, the transmitted energy of RCAC specimens was higher than that of NAC specimens. Microstructural analysis revealed that the morphology of recycled coral aggregate is characterized by its porous and rough surface. The interfacial transition zone between the recycled coral aggregate and the cement mortar was relatively dense. Incorporating recycled coarse aggregate significantly affected the drying shrinkage properties of the concrete, with higher contents of RCCA leading to greater drying shrinkage rates.

Analysis of geological disaster management and ecological restoration measures in mining engineering

This paper provides a comprehensive analysis of the current effective measures for managing geological disasters and ecological damage caused by mining engineering development. The discussion primarily focuses on two aspects: engineering technology and ecological management. It is clear that slope stabilization technology, drainage and waterproof system construction, vegetation restoration, and artificial humidity construction play active roles in the management of geological disasters and ecological restoration in mining areas. These measures not only effectively control geological disasters but also significantly improve the ecological environment, enhance the self-recovery capacity of regional ecosystems, and achieve harmonious development of society, economy, and environment.

Synergistic integration of isogeometric analysis and data-driven modeling for enhanced strip footing design on two-layered clays: Advancing geotechnical engineering practices

This study innovatively combines Isogeometric Analysis (IGA) with Machine Learning (ML) to assess strip footing bearing capacity on dual clayey layers. Overcoming limitations of conventional methods with small sample sizes, our research generates a dataset of 10,000 samples, allowing a thorough exploration of diverse soil profiles. Facilitated by ML, 10,000 IGA analyses using upper bound limit analysis unveil intricate patterns and relationships previously obscured. The key innovation lies in harnessing big data and employing advanced data visualization, particularly 2D and 3D Partial Dependency Plots (PDPs). These PDPs visually showcase the impact of factors such as upper layer thickness, cohesion ratios, shear strength profiles, footing depth, and foundation roughness on bearing capacity. Offering intuitive insights, these visualization tools enhance comprehension, aiding informed decision-making in design and construction. Engineers and geotechnical experts receive a precise predictive tool, optimizing strip footing performance on clayey soil layers. Moreover, this research contributes to advancing geotechnical engineering by enriching fundamental knowledge of load-bearing characteristics. In summary, the fusion of big data, advanced visualization, and upper bound limit analysis, exemplified by PDPs, signifies a substantial leap in geotechnical engineering, impacting design, construction, and infrastructure development.

Thermal, surface, and structure analysis of molybdenum substituted bioactive glass ceramics SiO2-CaO- MoO3-P2O5

This study explores the incorporation of molybdenum oxide (MoO3) as a dopant in SiO2-CaO-P2O5 (BGC) glass-ceramics through a meticulously designed sol-gel synthesis process to optimize properties for regenerative medicine applications. Comprehensive characterization techniques, including thermal analysis (TGA/DSC), Raman spectroscopy, scanning electron microscopy (SEM), X-ray diffraction (XRD), and Fourier-transform infrared spectroscopy (FTIR), elucidate the morphological and structural modifications induced by MoO3 doping. Results reveal that MoO3 affects the glass transition temperature, crystallization behavior, and surface morphology, leading to enhanced glass stability, crystallinity, and surface properties. The mechanical properties, such as fracture toughness, also significantly improved with MoO3 doping due to the formation of crystalline phases and densification of the material structure. Notably, the doping of MoO3 promotes the formation of CaMoO4 crystalline phases and influences the synthesis of hydroxyapatite—critical for bone tissue regeneration—when immersed in simulated body fluid (SBF). The study highlights the hydrophilic nature of the doped samples, facilitating bone development and cell adhesion, while also showing that increased MoO3 content reduces the rate of hydroxyapatite formation and material degradability. These findings demonstrate that MoO3 doping via the sol-gel method offers a promising approach for tailoring BGC glass-ceramics' properties, making them more suitable for regenerative medicine applications. This research underscores the potential of MoO3 in advancing biomaterial development for tissue engineering and implantology.

Application and performance evaluation of recycled building materials in civil engineering

The concept of renewable materials has received extensive advocacy and promotion in the ongoing development of the construction industry. Furthermore, emerging renewable building materials, such as bio-based composite materials, are continually evolving and gradually being incorporated into civil engineering applications. This paper focuses on the application and performance assessment of recycled building materials in civil engineering. As a crucial component of environmental protection and sustainable development, recycled building materials possess vast potential for application. In this article, the characteristics of common materials such as recycled concrete, recycled steel, and recycled glass are introduced, and their mechanical performance, durability, and other vital attributes are evaluated. Finally, the feasibility and challenges of recycled building materials are analyzed, along with discussions on sustainable development strategies and policy support. The comprehensive research results demonstrate the significant role of recycled building materials in promoting sustainable development in civil engineering, warranting increased support and promotion at the policy and societal levels.

Turbocharger turbine map scaling for virtual engine use

Emissions requirements, performance expectations, and expanding range of fuels for off-road engines are broadening engine air system requirements. As part of reducing engine development cost and risk, virtual engine simulation is used to select architecture and components capable of covering a broad range of requirements through low risk changes to the turbocharger turbine. A method is presented for predicting turbine performance changes due to turbine housing area change, the most effective of these low risk changes, from available turbine map data. The method, developed from a mean line model, learns four simplified geometry parameters, three loss coefficients, and two maximum efficiency rotor inlet incidence coefficients from a training turbine map data set, then predicts a scaled turbine map for changes to a simplified geometry parameter associated with housing area. Reduced mass flow RMS errors less than 4.3% and efficiency RMS errors less than 5.2% are expected when generating scaled turbine maps with this method, which is additional 2% error for flow and 3% error for efficiency over that expected when modeling actual turbine map data.

Energy evolution and damage model of sandstone under seepage-creep-disturbance loading

The geological environment of deep coal seam is complex, and the failure mechanism of coal seam under the action of seepage pressure and disturbance stress is unclear, which restricts the development of deep ground engineering. In this study, triaxial compression test of sandstone under seepage-creep-disturbance loading (SCD) was carried out to analyze the characteristics of disturbance deformation, creep rate and permeability. The focus was on the energy evolution law of sandstone under SCD, and the damage creep model was constructed based on the energy proportion. The results show that the creep increment of sandstone under disturbed load was significantly higher than that under undisturbed load, and the stress level can promote the expansion and development of microcracks, in which the creep increment under high stress level showed a jump increase. The total energy and elastic energy of sandstone showed a step change with time. The damage factor under disturbance load was defined in the form of energy dissipation ratio, and the corresponding coupling damage factor was determined by considering the seepage factor and creep factor, which can reflect the coupled damage deformation of sandstone under SCD. Based on fractional order theory, a nonlinear damage creep model describing sandstone deformation under SCD was established by connecting the acceleration element in series with the Nishihara model and introducing the coupling damage factor. This study can provide research ideas for water inrush of coal seam rock mass.

SyDRA: An approach to understand game engine architecture

Game engines are tools to facilitate video game development. They provide graphics, sound, and physics simulation features, which would have to be otherwise implemented by developers. Even though essential for modern commercial video game development, game engines are complex and developers often struggle to understand their architecture, leading to maintainability and evolution issues that negatively affect video game productions. In this paper, we present the Subsystem-Dependency Recovery Approach (SyDRA), which helps game engine developers understand game engine architecture and therefore make informed game engine development choices. By applying this approach to 10 open-source game engines, we obtain architectural models that can be used to compare game engine architectures and identify and solve issues of excessive coupling and folder nesting. Through a controlled experiment, we show that the inspection of the architectural models derived from SyDRA enables developers to complete tasks related to architectural understanding and impact analysis in less time and with higher correctness than without these models.

Early-stage Development of the CoRISMA Mechanical Circulatory Support (CMCS) System for Heart Failure Therapy.

CoRISMA MCS Systems Inc (Hamden CT) is developing an innovative mechanical circulatory support system (CMCS) as a durable therapeutic option for heart failure (HF) patients. The CMCS system is comprised of an axial flow pump, non-contacting hydrodynamic bearings, and integrated DC motor designed to be fully implantable in a left atrial (LA) to aortic (Ao) configuration; this unloading strategy may be particularly beneficial for HF patients with preserved ejection fraction (HFpEF). The small (5.5 cm3), lightweight (20g), and low power (5-7W) device design should allow for a less invasive off-pump implant. We present early-stage engineering development and testing of the prototype CoRISMA pumps. Computational fluid dynamics (CFD) modeling was performed to evaluate flow and shear in two impeller (3 blades, 0.5mm thickness, 8.9mm diameter, 0.15mm gap, polished titanium) and diffusor (5 blades, polished titanium) candidate designs. Test apparatuses were custom built to expedite development of the impeller/diffuser designs and iteratively refine the CFD models. Two candidate impeller/diffusor designs were fabricated and tested in each of the two test apparatuses (n = 4 impeller/diffuser + test fixture configurations) in static mock flow loops (hydrodynamic H-Q curves, 3.5 cP glycerol solution at 37°C), and in dynamic mock flow loops (hemodynamics, 3.5 cP glycerol solution at 37°C) tuned to HF conditions (mean aortic pressure 50 mmHg, central venous pressure 15 mmHg, aortic flow 3.0L/min, and heart rate 80bpm). CFD predicted flows of 4.56L/min and 4.82L/min at 100 mmHg for impellers/diffusers 1 and 2, respectively. Impeller 2 required less torque to generate a 6% increase in fluidic flow, and the diffuser had a larger area of high pressure, indicative of lower friction, which likely contributed to the increased efficiency. Experimental testing for all four configurations in the static and dynamic mock loops met performance metrics as evidenced by generating 4.0-4.5L/min flow against 70-76 mmHg pressure at 25,000rpm and restoring hemodynamics in the dynamic mock flow loop (MAP = 80 mmHg, CVP = 0 mmHg, total flow = 5.5L/min) from baseline simulated HF test conditions. These results demonstrate proof-of-concept of the early engineering design and performance of the prototype CoRISMA pumps. Engineering specifications, challenges observed, and proposed solutions for the next design iteration were identified for the continued development of an effective, reliable, and safe LA-to-Ao CMCS system for HF patients. Current design plans are underway for incorporating a wireless energy transfer system for communication and power, eliminating the need for and complications associated with an external driveline, to achieve a fully-implantable system.

Unraveling the mystery of sandwich structure: Emerging photocatalytic hydrogen production by g-C3N5 coupled Nb2C MXene forming Schottky heterojunction

The development of new photocatalysts and photocatalytic systems is the essence of the development of photocatalytic hydrogen production engineering. Nitrogen-rich graphite carbon nitride (g-C3N5) has gradually replaced conventional graphite phase carbon nitride (g-C3N4) with a smaller bandgap and high-efficiency visible light utilization. In this study, g-C3N5 and Nb2C MXene coupled composition with sandwich structure were manufactured by a simple ultrasonic magnetic stirring method and used for photocatalytic hydrogen production. By adjusting the ratios of single components in the system, the hydrogen production rate of the optimal sample 4:1g-C3N5/Nb2C under visible light irradiation is 2529.5 μmol·g−1·h−1, which is 21 times higher than that of g-C3N5. The high apparent quantum yield (AQY) value of 17.3 % also proves a high light utilization rate. The atomic force microscopy (AFM) technique reveals variations in the thickness of the samples, while strongly demonstrating the formation of sandwich structure. In addition, X-ray photoelectron spectroscopy (XPS) analysis further reveals the electron transfer paths within the system, preliminarily verifying the formation of Schottky heterojunctions. Kelvin probe force microscopy (KPFM) tests not only re-validate the correctness of the electron transfer path but also demonstrate the accuracy of the energy bands. The density-functional theory (DFT) calculations corroborate that Nb2C MXene plays the role of a photoco-catalyst to form Schottky heterojunctions with g-C3N5 for efficient carrier separation and migration. This work highlights the key role of sandwich structure photocatalytic systems on photocatalytic performance.

A molecular dynamics study on pore structure: Performance comparison between metal foam and artificial mesh porous surface

With the development of surface engineering, porous surfaces have emerged as a significant research subject in boiling heat transfer. The latter, in turn, plays a crucial role in various industries such as power plants, distillation plants, and microelectronic technology. In this paper, the Molecular Dynamics method is adopted to investigate the wicking dynamics and boiling dynamics of two porous surfaces: foam, which exhibits randomly distributed pores, and mesh, composed of ordered square wires with relatively uniform pore sizes. Three wettability, namely hydrophilic, neutral, and hydrophobic wetting states, are assigned to the two porous surfaces de-coupling the effect of wettability from surface structure. Results reveal that, during the wicking process, the foam surface shows better wetting ability as it absorbs liquid under both hydrophilic and neutral wettability. Comparatively, the mesh surface has the fastest wicking speed under hydrophilic wettability yet it becomes non-wetting under neutral wettability. During the boiling process, the boiling dynamics differ greatly under three wettability. More importantly, the difference in surface structure makes the foam surface possess a better heat transfer whereas the mesh surface causes gentle pressure variation. Our findings provide insights into the design of artificial porous surfaces for certain purpose and their potential application.

A Genomewide Evolution-Based CRISPR/Cas9 with Donor-Free (GEbCD) for Developing Robust and Productive Industrial Yeast.

Developing more robust and productive industrial yeast is crucial for high-efficiency biomanufacturing. However, the challenges posed by the long time required and the low abundance of mutations generated through genomewide evolutionary engineering hinder the development and optimization of desired hosts for industrial applications. To address these issues, we present a novel solution called the Genomewide Evolution-based CRISPR/Cas with Donor-free (GEbCD) system, in which nonhomologous-end-joining (NHEJ) repair can accelerate the acquisition of highly abundant yeast mutants. Together with modified rad52 of the DNA double-strand break repair in Saccharomyces cerevisiae, a hypermutation host was obtained with a 400-fold enhanced mutation ability. Under multiple environmental stresses the system could rapidly generate millions of mutants in a few rounds of iterative evolution. Using high-throughput screening, an industrial S. cerevisiae SISc-Δrad52-G4-72 (G4-72) was obtained that is strongly robust and has higher productivity. G4-72 grew stably and produced ethanol efficiently in multiple-stress environments, e.g. high temperature and high osmosis. In a pilot-scale fermentation with G4-72, the fermentation temperature was elevated by 8 °C and ethanol production was increased by 6.9% under the multiple stresses posed by the industrial fermentation substrate. Overall, the GEbCD system presents a powerful tool to rapidly generate abundant mutants and desired hosts, and offers a novel strategy for optimizing microbial chassis with regard to demands posed in industrial applications.