Development Of Engineering Technology Research Articles

Mesenchymal stem cells in craniofacial reconstruction: a comprehensive review.

Craniofacial reconstruction faces many challenges, including high complexity, strong specificity, severe injury, irregular and complex wounds, and high risk of bleeding. Traditionally, the "gold standard" for treating craniofacial bone defects has been tissue transplantation, which involves the transplantation of bone, cartilage, skin, and other tissues from other parts of the body. However, the shape of craniofacial bone and cartilage structures varies greatly and is distinctly different from ordinary long bones. Craniofacial bones originate from the neural crest, while long bones originate from the mesoderm. These factors contribute to the poor effectiveness of tissue transplantation in repairing craniofacial defects. Autologous mesenchymal stem cell transplantation exhibits excellent pluripotency, low immunogenicity, and minimally invasive properties, and is considered a potential alternative to tissue transplantation for treating craniofacial defects. Researchers have found that both craniofacial-specific mesenchymal stem cells and mesenchymal stem cells from other parts of the body have significant effects on the restoration and reconstruction of craniofacial bones, cartilage, wounds, and adipose tissue. In addition, the continuous development and application of tissue engineering technology provide new ideas for craniofacial repair. With the continuous exploration of mesenchymal stem cells by researchers and the continuous development of tissue engineering technology, the use of autologous mesenchymal stem cell transplantation for craniofacial reconstruction has gradually been accepted and promoted. This article will review the applications of various types of mesenchymal stem cells and related tissue engineering in craniofacial repair and reconstruction.

Transplantation of Neural Stem Cells Loaded in an IGF-1 Bioactive Supramolecular Nanofiber Hydrogel for the Effective Treatment of Spinal Cord Injury.

Spinal cord injury (SCI) leads to massive cell death, disruption, and demyelination of axons, resulting in permanent motor and sensory dysfunctions. Stem cell transplantation is a promising therapy for SCI. However, owing to the poor microenvironment that develops following SCI, the bioactivities of these grafted stem cells are limited. Cell implantation combined with biomaterial therapies is widely studied for the development of tissue engineering technology. Herein, an insulin-like growth factor-1 (IGF-1)-bioactive supramolecular nanofiber hydrogel (IGF-1 gel) is synthesized that can activate IGF-1 downstream signaling, prevent the apoptosis of neural stem cells (NSCs), improve their proliferation, and induce their differentiation into neurons and oligodendrocytes. Moreover, implantation of NSCs carried out with IGF-1 gels promotes neurite outgrowth and myelin sheath regeneration at lesion sites following SCI. In addition, IGF-1 gels can enrich extracellular vesicles (EVs) derived from NSCs or from nerve cells differentiated from these NSCs via miRNAs related to axonal regeneration and remyelination, even in an inflammatory environment. These EVs are taken up by autologous endogenous NSCs and regulate their differentiation. This study provides adequate evidence that combined treatment with NSCs and IGF-1 gels is a potential therapeutic strategy for treating SCI.

Cardiac Amyloidosis: A Contemporary Review of Medical and Surgical Therapy.

Amyloidosis is a systemic disease initiated by deposition of misfolded proteins in the extracellular space, due to which multiple organs may be affected concomitantly. Cardiac amyloidosis, however, remains a major cause of morbidity and mortality in this population due to infiltrative /restrictive cardiomyopathy. This review attempts to focus on contemporary medical and surgical therapies for the different types of cardiac amyloidosis. Amyloidosis affecting the heart are predominantly of the transthyretin type (acquired in the older or genetic in the younger patients), and the monoclonal immunoglobulin light chain (AL) type which is solely acquired. A rare form of secondary amyloidosis AA type can also affect the heart due to excessive production and accumulation of the acute-phase protein called Serum Amyloid A" (SAA) in the setting of chronic inflammation, cancers or autoinflammatory disease. More commonly AA amyloidosis is seen in the liver and kidney. Other rare types are Apo A1 and Isolated Atrial Amyloidosis (AANF). Medical therapies have made important strides in the clinical management of the two common types of cardiac amyloidosis. Surgical therapies such as mechanical circulatory support and cardiac transplantation should be considered in appropriate patients. Future research using AI driven algorithms for early diagnosis and treatment as well as development of newer genetic engineering technologies will drive improvements in diagnosis, treatment and patient outcomes.

Biomimetic fabrication of sr-silk fibroin co-assembly hydroxyapatite based microspheres with angiogenic and osteogenic properties for bone tissue engineering

Bone defects caused by trauma, tumor resection, or developmental abnormalities are important issues in clinical practice. The vigorous development of tissue engineering technology provides new ideas and directions for regenerating bone defects. Hydroxyapatite (HAp), a bioactive ceramic, is extensively used in bone tissue engineering because of its excellent osteoinductive performance. However, its application is challenged by its single function and conventional environment-unfriendly synthesis methods. In this study, we successfully "green" synthesized sr-silk fibroin co-assembly hydroxyapatite nanoparticles (Sr-SF-HA) using silk fibroin (SF) as a biomineralized template, thus enabling it to have angiogenic activity and achieving the combination of organic and inorganic substances. Then, the rough composite microspheres loaded with Sr-SF-HA (CS/Sr-SF-HA) through electrostatic spraying technology and freeze-drying method were prepared. The CCK-8 test and live/dead cell staining showed excellent biocompatibility of CS/Sr-SF-HA. Alkaline phosphatase (ALP) staining, alizarin red staining (ARS), immunofluorescence, western blotting, and qRT-PCR test showed that CS/Sr-SF-HA activated the expression of related genes and proteins, thus inducing the osteogenic differentiation of rBMSCs. Moreover, tube formation experiments, scratch experiments, immunofluorescence, and qRT-PCR detection indicated that CS/Sr-SF-HA have good angiogenic activity. Furthermore, in vivo studies showed that the CS/Sr-SF-HA possesses excellent biocompatibility, vascular activity, as well as ectopic osteogenic ability in the subcutaneous pocket of rats. This study indicates that the construction of CS/Sr-SF-HA with angiogenic and osteogenic properties has great potential for bone tissue engineering.

Characteristics of students’ learning behavior preferences — an analysis of self-commentary data based on the LDA model

How to better grasp students’ learning preferences in the environment of rapid development of engineering and science and technology so as to guide them to high-quality learning is one of the important research topics in the field of educational technology research today. In order to achieve this goal, this paper utilizes the LDA (Latent Dirichlet Allocation) model for text mining of the survey results on the basis of a survey on students’ self-perception evaluation. The results show that the LDA model is capable of extracting terms from text, fuzzy identifying groups of students at different levels and presenting potential logical relationships between the groups, and further analyzing the learning preferences of students at different levels for IT courses. Based on the student’s learning needs, this paper proposes recommendations for developing students’ learning effectiveness. The LDA method proposed in this paper is a feasible and effective method for assessing students’ learning dynamics as it generates cognitive content about students’ learning and allows for the timely discovery of students’ learning expectations and cutting-edge dynamics.

Integration and Development of Reverse Engineering and Digital Manufacturing Technology

Integration and Development of Reverse Engineering and Digital Manufacturing Technology

The application of biomimetic limbs in postoperative rehabilitation of amputees

Due to the inability to provide recovery opportunities, amputation is generally considered a failure of treatment. Traditional prostheses cannot interact with the surrounding environment, and the contact surface between the prosthesis and the residual limb is prone to wear and tear, causing pain to patients. Therefore, prostheses are generally regarded by patients as tools rather than a part of the body. In recent years, with the continuous development of artificial intelligence, materials science, and biomedical engineering technology, bionic limb technology has received widespread attention and application. Currently, bone integration and electromyography interface technology are widely applied in bionic limbs, allowing for more realistic and diverse options for prostheses for patients. Material innovation and machine learning technology can improve the mechanical performance, perceptual feedback effects, and autonomous learning ability of bionic limbs, but further research and exploration are still needed. This review paper aims to summarize and evaluate the current development status, application areas, and future research directions of bionic limb technology.

Modelling of the impact of burnishing force on average surface roughness

As a result of the development of engineering technology, new opportunities and methods are constantly being developed to examine individual material structure changes, but most of these are impossible to implement on a low budget. Tests carried out with finite element simulations enable the optimization of machining processes and the reduction of experimental costs. The paper discusses the modelling of burnishing process that can effectively reduce surface roughness and the effect of burnishing force on average surface roughness. The machining is simulated using DEFORM-2D software, corresponding to the values of the experimental parameters (burnishing force, feed, speed) implemented in practice, allowing a comparative analysis of the material quality of low alloyed aluminium.

The designation of intrinsic flame-retarding vinyl ester resins with high mechanical property, optical transparency and degradability

With the rapid development of engineering technology, it is urgent to design vinyl ester resins (VER) with excellent flame retardancy, high mechanical properties, transparency and degradability to satisfy the high requirements of transportation and aerospace fields. Therefore, a curing agent (DP) with multi flame-retarding elements, aromatic ring and triazine structure was fabricated via simple salt-forming reaction between the PA and DDT. For the VERDP10, the tensile strength and flexural strength increased by 54.3 % and 30.3 % comparing to that of VER, and the light transparency kept at a high level. Meanwhile, the VERDP10 material can be chemically degraded via the hydrolysis of ester bonds under high temperature and high pressure with the catalyst. The VERDP10 material passed the UL-94V-0 rating at a LOI of 32.2 %. The peak of heat release rate (PHRR) and total heat release (THR) decreased by 56.3 % and 36.1 % comparing to that of VER respectively. Moreover, an obvious expanded flame-retarding effect in the condensed phase accompanied with moderate gas-phase effect jointly functioned to the excellent flame retardancy of the VERDP10.

Assessing the Durability and Acoustic Performance of a Novel Two-Layer Pavement System

In the quest for more sustainable pavement solutions, this study demonstrates the successful strengthening of a unique noise-reducing two-layer road surface. While existing noise-reducing pavements reveal high acoustic efficiency, they lack mechanical strength, and earlier research efforts addressed the optimization of the individual components of this system, and a comprehensive perspective on its integrated performance remained elusive. Therefore, this research bridges this knowledge gap through an in-depth laboratory evaluation, in which the requirements for the realization of a full-scale demonstrator were defined, followed by a comprehensive performance assessment in terms of acoustic and mechanical strength. The post-construction assessment reveals the system’s multifaceted strengths, considering noise reduction, resilience under heavy traffic, pavement deflections, and skid resistance, assessed by CPX measurements, accelerated pavement tests using the MLS 30, skid resistance tests employing the pendulum test, as well as the slow-moving longitudinal friction test (MicroGriptester) and falling weight deflectometer (FWD) measurements. Although the optimized system implies lower noise-reduction potential, it exhibits great strength compared to previous noise-reducing pavements. In general, the system offers viable noise mitigation solutions for urban highways, particularly in settings where traditional noise abatement measures are constrained by space. The insights from this study serve as a valuable reference for the development and evaluation of innovative road engineering materials and technologies.

Application analysis and evaluation of BIM in engineering design and construction stages

With the development of modern engineering technology, more attention is paid to the aid of digitization and information in the process of engineering project design and construction. Building Information Model (BIM) realizes the transformation from traditional building project to modern building project. At the same time, it also greatly promotes the digital development of construction projects. BIM technology as a modern information technology in the application of construction engineering, has a variety of benefits. For example, it can improve the quality of projects. In addition, the application of BIM technology in the whole process of construction projects can reduce costs and improve efficiency. However, there are many risks associated with using BIM in construction projects. This paper analyzes the advantages of BIM technology in visualization and coordination, and the application of BIM in design, construction, management and other aspects. Then, the risks and countermeasures in BIM application are discussed. The research results are of great significance to improve the informatization level of construction projects.

Design of an Artificial Peptide Inspired by Transmembrane Mitochondrial Protein for Escorting Exogenous DNA into the Mitochondria to Restore their Functions by Simultaneous Multiple Gene Expression

AbstractMitochondria are vital organelles regulating essential cellular functions. Human mitochondrial DNA (mtDNA) consists of 37 genes, 13 of which encode mitochondrial proteins, and the remaining 24 genes encode two ribosomal RNAs and 22 transfer RNAs needed for the translation of the mtDNA‐encoded 13 proteins. However, mtDNA often impairs the expression and function of these genes due to various mutations, ultimately causing mitochondrial dysfunction. To recover from this desperate condition, developing the technology to supply all mitochondrial proteins encoded by mtDNA at once is an urgent task, but there is no established strategy for this purpose. In this study, a simple yet effective mitochondrial gene delivery system is proposed comprising an artificial peptide inspired by a transmembrane mitochondrial membrane protein. The designed mitochondria‐targeting peptides presented on the carrier surface effectively guide the encapsulated plasmid to the mitochondria, facilitating mitochondrial uptake and gene expression. The developed system successfully delivers exogenous mtDNA to mtDNA‐depleted cells and leads to simultaneous multigene expression, ultimately restoring mitochondrial functions, including the mitochondrial respiration rate. The established multiple gene expression system in each mitochondrion is a game‐changing technology that can accelerate the development of mitochondrial engineering technologies as well as clinical applications for mitochondrial diseases.

Research on the Application and Performance Optimization of GPU Parallel Computing in Concrete Temperature Control Simulation

With the development of engineering technology, engineering has higher requirements for the accuracy and the scale of simulation calculation. The computational efficiency of traditional serial programs cannot meet the requirements of engineering. Therefore, reducing the calculation time of the temperature control simulation program has important engineering significance for real-time simulation of temperature field and stress field, and then adopting more reasonable temperature control and crack prevention measures. GPU parallel computing is introduced into the temperature control simulation program of massive concrete to solve this problem and the optimization is carried out. Considering factors such as GPU clock rate, number of cores, parallel overhead and Parallel Region, the improved GPU parallel algorithm analysis indicator formula is proposed. It makes up for the shortcomings of traditional formulas that focus only on time. According to this formula, when there are enough threads, the parallel effect is limited by the size of the parallel domain, and when the parallel domain is large enough, the efficiency is limited by the parallel overhead and the clock rate. This paper studies the optimal Kernel execution configuration. Shared memory is utilized to improve memory access efficiency by 155%. After solving the problem of bank conflicts, an accelerate rate of 437.5× was realized in the subroutine of the matrix transpose of the solver. The asynchronous parallel of data access and logical operation is realized on GPU by using CUDA Stream, which can overlap part of the data access time. On the basis of GPU parallelism, asynchronous parallelism can double the computing efficiency. Compared with the serial program, the accelerate rate of inner product matrix multiplication of the GPU asynchronous parallel program is 61.42×. This study further proposed a theoretical formula of data access overlap rate to guide the selection of the number of CUDA streams to achieve the optimal computing conditions. The GPU parallel program compiled and optimized by the CUDA Fortran platform can effectively improve the computational efficiency of the simulation program for concrete temperature control, and better serve engineering computing.

Recent advances in enzymatic properties, preparation methods, and functions of glycoside hydrolase from Bifidobacterium: a review.

Bifidobacterium is a major probiotic of intestinal gut flora and exerts many physiological activities, and it is widely applied in the fields of food and medicine. As an important part of Bifidobacterium, glycoside hydrolase plays a role in its physiological activity. With the continuous development and improvement of genetic engineering technology, research on this type of enzyme will play a crucial role in promoting the further development of Bifidobacterium in the field of probiotics. In this review, the preparation methods, enzymatic properties, and functions of glycoside hydrolase extracted from Bifidobacterium are described and summarized. The common method for preparing glycoside hydrolase derived from Bifidobacterium is heterologous expression in Escherichia coli BL21. The optimal pH range for these glycoside hydrolase enzymes is between 4.5 and 7.5; the optimal temperature is between 30 and 50 °C, which is close to the optimal growth condition of Bifidobacterium. Based on substrate specificity, these glycoside hydrolase could hydrolyze synthetic substrates and natural oligosaccharides, including a series of pNP artificial substrates, disaccharide, and trisaccharides, while they have little ability to hydrolyze polysaccharide substrates. This review will be expected to provide a basis for the development of Bifidobacterium as a probiotic element.

Development of Reinforced Concrete Piles in the Lower Yellow River, China

Controlling the river regime in the lower wandering reaches of the Yellow River Basin is important for ecological protection and high-quality development. This study reviews the development of pile groynes suitable for wandering rivers. As a widely used form of reinforced concrete pile, pile groynes, including round and sheet piles, have been built in alluvial rivers in large numbers for many years. Currently, research focuses on improving the stability and erosion resistance of these piles. Here, three types of groynes are discussed according to the construction technology: cast-in situ bored pile, vibratory-driven pile, and jetted precast concrete pile. Detailed discussions are provided regarding their respective applicability, improvement processes and characteristics. In contrast to the other two methods, jetting minimizes the damage to the structure and strength of the concrete pile and is characterized as fast-tracking, cost-effective, and environmentally friendly. Enhancing the safety and practicality of concrete piles can be effectively achieved through improvements in construction techniques, modified construction materials, and multi-structure combination pile designs. Furthermore, in the current context of pursuing a resource-saving and environmentally friendly society, energy conservation and emissions reduction have become focal points in engineering technology development, while still maintaining a strong emphasis on construction quality.

Calculation of multi-blade rotary-friction tool shaft for strength

The leading place in the technology of modern mechanical engineering production is occupied by cutting processes. In many branches of mechanical engineering, especially in mass production, their labor and production costs reach 40-60% of the total costs of metalworking. Nowadays, no more or less complex machine can be made without the use of cutting tools. Thus, we can rightfully assert that cutting machining has retained its predominant influence on the development of mechanical engineering technology and its importance will be steadily increasing in the future, largely based on the use of fundamentally new machining methods. And the latter can be rightly attributed to the so-called rotary cutting. The authors have developed a design of a special multi-blade rotary-friction tool for machining cylindrical surfaces of parts made of hard-to-machine materials. This paper presents the results of the calculation of the most loaded node of the multi-blade rotary-friction tool of the part “shaft”. Calculation of the bending strength of the shaft has been performed. The results of the calculation have been checked through the program Apm Winmachine which has confirmed their correctness. This research is funded by the Ministry of Science and Higher Education of the Republic of Kazakhstan (Grant No. AP14972884).

유전공학 기술에 대한 한국인들의 인식과 정책적 시사점

The purpose of this study is to investigate the policy implications by examining the citizen perception of genetic engineering technology. To this end, this study conducted an online survey targeting 1,000 adults, analyzed the awareness and acceptance of three areas, such as genetic testing, gene editing, and national integrated bio big data construction project, and derive policy implications. According to the survey analysis, first, education and income have a significant impact on awareness of genetic engineering technology, second, acceptance of genetic engineering technology is closely related to age and whether or not there is a genetic disease in the family, and third, gene editing differs in pros and cons or future intentions depending on the purpose. Fourth, citizens recognize that genetic engineering technology will have an impact on the improvement of the quality of life and infringement of rights of individuals at the same time, and fifth, unlike overseas, religious and gender variables in Korea have relatively little effect. These results imply variables and factors to be considered in responding to the development of genetic engineering technology and subsequent social changes, and this study is expected to provide meaningful theoretical foundations, social indicators, and policy implications in the process of establishing policies and institutions in the future.

Biopolymers and Their Application in Bioprinting Processes for Dental Tissue Engineering.

Dental tissues are composed of multiple tissues with complex organization, such as dentin, gingiva, periodontal ligament, and alveolar bone. These tissues have different mechanical and biological properties that are essential for their functions. Therefore, dental diseases and injuries pose significant challenges for restorative dentistry, as they require innovative strategies to regenerate damaged or missing dental tissues. Biomimetic bioconstructs that can effectively integrate with native tissues and restore their functionalities are desirable for dental tissue regeneration. However, fabricating such bioconstructs is challenging due to the diversity and complexity of dental tissues. This review provides a comprehensive overview of the recent developments in polymer-based tissue engineering and three-dimensional (3D) printing technologies for dental tissue regeneration. It also discusses the current state-of-the-art, focusing on key techniques, such as polymeric biomaterials and 3D printing with or without cells, used in tissue engineering for dental tissues. Moreover, the final section of this paper identifies the challenges and future directions of this promising research field.

Occurrence, fate and potential health risks of antibiotic resistomes in a constructed wetlands-reservoir ecosystem for drinking water source improvement

The development of effective and feasible engineering technologies to control the transmission of antibiotic resistance genes (ARGs) and pathogenic antibiotic-resistant bacteria (PARB) form drinking water sources is urgently needed for ensuring drinking water safety. In this study, metagenomic analysis was applied to systematically explore the full profiles, removal, and potential health risks of antibiotic resistomes in a large constructed wetlands-reservoir ecosystem (CWs-R) for drinking water source improvement. A total of 343 ARG subtypes belonging to 18 ARG types were identified from water and sediment samples in the CWs-R ecosystem, with an average abundance of 0.339 copies/cell, and bacitracin and multidrug resistance genes were the predominant ARG types in the water and sediment, respectively. The CWs-R ecosystem showed an excellent removal efficiency of ARGs and mobile genetic elements (MGEs) in water, with the total removal rate reaching 64.82 % and 77.09 %, respectively, among which the emergent plant zone and ecological storage unit played major roles. The metagenomic assembly tracked many mobile ARGs and opportunistic pathogens in the CWs-R ecosystem and identified 19 contigs as ARG-carrying pathogens, including Staphylococcus aureus, Salmonella enterica, Escherichia coli, and Klebsiella pneumonia. Overall, the CWs-R ecosystem has an important role in reducing the potential public health risks posed by antibiotic resistomes in drinking water sources but still cannot fully eliminate them. Therefore, we further classified water and sediment samples in the CWs-R ecosystem and identified potential ARGs and PARB indicators based on the metagenomic analysis results by considering the potential for horizontal transfer of ARGs to opportunistic pathogens. Taken together, this work demonstrates the CWs-R ecosystem as an economical and feasible engineering technology to reduce the dissemination of antibiotic resistomes in the drinking water source, provides useful information for monitoring and controlling antibiotic resistance in similar water sources, and ensures biosafety of drinking water.

PREPARATION OF DRUG-LOADED CHITOSAN/HYDROXYAPATITE COMPOSITE MATERIAL AND ITS NUMERICAL SIMULATION IN NASAL DEFECT REPAIR

With the continuous innovation and development of materials science and tissue engineering technology, biomaterials are gradually being used to replace autologous bone and allogeneic bone grafts in clinical practice for the treatment and repair of bone defects. In this paper, L-arginine-modified chitosan/hydroxyapatite composites were prepared by solution blending of L-arginine-modified chitosan and hydroxyapatite. A hormone drug prednisone acetate was loaded into the composites by supercritical impregnation technique. The results of in vitro release showed that under the loading condition of 12 MPa and 318 K, the cumulative release amount of the drug was 74.6% in 72 h, which had an excellent sustained release effect. In addition, a numerical model of the nasal bone was developed and numerical calculations were performed to analyze and compare the stresses of the healthy nasal bone and the nasal bone repaired with CA/HA composite when subjected to a force of 100 N, in different directions. The total deformation difference at the material was 0.002-0.004 mm/mm, and the stress difference was 0.004–1.373 MPa for the nasal bone in both states, with the sagittal plane under 0–90 degrees of force. The above results indicate that the CA/HA composite has good biological and mechanical properties and can be used to repair nasal bone defects. This material and numerical calculation method can also be applied to other related bone tissue engineering and biomedical materials, which have broad application prospects.