Computer-assisted Design Research Articles

Computer-Aided Development of New Nonlinear Optical Materials.

Exploring new nonlinear optical (NLO) materials is an urgent need for advanced photoelectric technologies. However, the discovery of new materials with targeted properties is time-consuming, and involves various challenges by the traditional trial-and-error experiments. Recently, the theoretical prediction-guided structural design has been demonstrated as a feasible way for efficiently developing new NLO materials, and a large number of NLO candidates with excellent optical properties have been explored. To promote the development of high-performance NLO materials, this review provides a summary on the exploration of new NLO materials aided by computer, with a particular emphasis on the state-of-the-art research advances that including crystal structure predictions, optical & thermal property calculations, high-throughput screening of NLO materials with or without machine learning; and the progress achieved in the computer-assisted design and development of new deep ultraviolet (DUV), ultraviolet (UV), infrared (IR) NLO materials in various material systems: oxide, chalcogenide, nitride, and halide. Finally, the opportunities and forthcoming challenges in the fascinating field are discussed.

Molecular Characterization of SHV, BLA-OXA and B-Lactamase Resistant Genes Leading to Computational Based Inhibitor Screening Against Bacillus Species

Antibiotic resistance in bacterial pathogen is a great challenge that is connected with excessive morbidity and mortality of living beings. A common motive of antibiotic resistance in bacteria is an increased abundance of Β- lactamases. There chromosomal Β- lactamases do not generally provide effective antibiotic resistance in wild type Bacilli despite evidence that the genes are not completely silenced. Under antibiotic selection pressure however, a number of strains show increased resistance suggesting mutation induced up regulation of Β- lactamases. Computer-assisted drug design has made significant progress in predicting biologically active molecules and their receptor binding conformation, with results that are sometimes more exact than those acquired through traditional methods like as high-throughput screening. The results of computational studies are sometimes more precise than the experimental possibilities, and they contribute to the improvement of the experimental array. In this study, identified pathogenic species of bacillus, and analyzed the antibiotic resistant genes. The Previous study of its characterization showed the presence of BLA-OXA and SHV genes in Bacillus cereus and Bacillus paramycoides. The sequenced antibiotics resistant genes were subjected to computational analysis for the interpretation of the potential inhibitors against BLA-OXA and SHV. The analyzed inhibitor will enable to study the diversity of antibiotic resistant mechanism and to minimize the resistance of bacterial species against antibiotics.

Utilizing 3D Model and Comparison Software Tools in Improving Assessment Methods: A Pilot Study

Purpose/Objectives: This manuscript investigates the effectiveness of computer-assisted design and manufacturing (CAD/CAM) technology in preclinical dental education. The COVID-19 pandemic created a need for remote teaching approaches. In preclinical fixed prosthodontics courses, traditional evaluation methods rely on faculty to visually grade laboratory projects utilizing rubrics and 2D images. Assessment and feedback vary amongst faculty, and faculty calibration has been inconsistent in reducing intra-and inter-rater variability. This study aimed to compare faculty assessment of student full coverage crown (FCC) preparations traditionally versus digitally through 3D model visual assessment and/or comparative analysis software reports. Methods: Eighteen UTHealth Houston School of Dentistry faculty participated, each randomly assigned into one of three assessment groups: traditional visual Group (TV), 3D Group (3D), and 3D visual assessment supplemented with comparative analysis software report (3D+) Group. Faculty graded the same eight lithium disilicate typodont preparations for all three assessment groups. Results: Survey results showed the ease of use and efficiency among the three assessment methods varied significantly. Grading scores revealed that axial wall reduction significantly differed among the three assessment methods. Conclusion: This study concludes that the combination of the two digital assessment methods can overcome the limitations of traditional evaluation methods and digital methods alone by providing objective feedback to students and enhancing their learning experience.

Can deep learning-designed anterior tooth-borne crown fulfill morphologic, aesthetic, and functional criteria in clinical practice?

ObjectivesThis study aimed to compare the design outcomes of anterior crowns generated using deep learning (DL)-based software with those fabricated by a technician using conventional dental computer-assisted design (CAD) software without DL support, with a focus on the evaluation of crown morphology, function, and aesthetics. MethodsTwenty-five in vivo datasets comprising maxillary and mandibular arch scans of prepared maxillary central incisors were utilized to design anterior crowns by using three methods: 1) a DL-based method resulting in as-generated outcome (DB), 2) a DL-based method further optimized by a technician (DM), and 3) a conventional CAD-based method (NC, control). Evaluations were conducted for crown morphology (total discrepancy volume (TDV), root mean square (RMS), positive average (PA) and negative average (NA) deviations), functional aspects (incisal path: deviations, length, and mean inclination), and aesthetics (crown width, height, width-to-height ratio, angular radius of mesioincisal line angle, proximal contact length, and tooth axis angle). ResultsSignificant differences in TDV ratio were noted between the DB–NC (32.3 ± 8.5 %) and DM–NC (26.5 ± 5.4 %) pairs (P = 0.006). No significant differences were observed in TDV between the DB–NC (65.3 ± 24.4 mm3) and DM–NC (54.3 ± 21.0 mm3) pairs (P = 0.095). For the entire palatal surface, significant differences in RMS and PA values were observed between the DB–NC and DM–NC pairs (P < 0.037). Significant differences in RMS values for the incisal half (P = 0.021) and in PA values for the cervical half (P = 0.047) of the palatal surface were also noted between these pairs. Significant differences in the deviation of the incisal path were observed between the DB–NC (290.4 ± 212.4 μm) and DM–NC (132.0 ± 122.3 μm) pairs (P < 0.001). However, no significant differences were found among the groups (DB, DM, and NC) in terms of the length and mean inclination of incisal paths or in aesthetic outcomes. ConclusionsA DL-based method can result in promising outcomes with clinically acceptable morphology and aesthetics for anterior crowns. Minor deviations in incisal path of the crowns may lead to anterior guidance discrepancies, which can be corrected by the dental technician at the design stage. Clinical significanceWith the potential of DL-based design methods in dental applications, integrating AI technology into dental CAD workflow can enhance the clinical efficiency and consistency of anterior crown design, although human intervention may be required to refine functional aspect.

Three‐Dimensional Printed Integrated Electrochemical Devices for Various Applications–A Review

AbstractThree‐dimensional Printing (3DP) and computer‐assisted design (CAD) are a boon for producing high‐quality analytical and electrochemical devices using low‐cost components. This review briefly explains various 3D printing techniques. The focus is on the fabrication of integrated miniature devices developed through the 3DP process, mainly by the Fused deposition modelling (FDM) technique. Examples of integrated electrochemical devices are presented to highlight the potential of 3DP. Special emphasis is given to surface activation of 3D printed electrodes to enhance their electrochemical activity and various activation methods. This paper discusses the opportunities and future applications in developing all‐in‐one miniature electrochemical devices that might lead to on‐site environmental measurements, point‐of‐care tests, and the development of portable instruments with reduced sample volume.

A Novel Technique for Repairing Alveolar Clefts: Computer-Assisted Design With Posterior of Mandible Block Bone Grafts

Objective: Iliac cancellous bone graft is the gold standard for the treatment of alveolar clefts. However, the resorption rate of iliac cancellous bone is generally high. In this study, the authors propose a new method for repairing alveolar clefts using block bone grafts in the posterior region of the mandibular molar and the anterior margin of the ascending branch. Methods: Ten patients with a diagnosis of unilateral or bilateral alveolar cleft were collected. Block bone grafting between the posterior mandibular molar region and the inner and outer oblique lines of the anterior margin of the ascending branch was used to treat the alveolar synostosis. Preoperative, 1-week postoperative, and 6-month postoperative multislice spiral computed tomography scans of the patients were collected and analyzed for preoperative design and postoperative graft bone morphology using computer-assisted software tools, which were also required to measure the changes in the bone tissue density in the posterior mandibular bone extraction area. Results: At 6 months postoperatively, the mean bone resorption rate of the posterior mandibular bone grafts for cleft alveolar processes was 33.96% ± 11.23%. Bone tissue density in the posterior mandibular bone grafting area recovered to near preoperative levels at 6 months postoperatively. Conclusion: The novel method of bone grafting for the cleft alveolar process used in this paper is really effective. Postoperative posterior mandibular bone extraction did not cause sequelae such as mandibular bone defects or poor morphology in the patients. Computer-assisted design and three-dimensional printing technology helped to improve intraoperative bone grafting accuracy and postoperative assessment.

Investigating the Antimicrobial Properties of Essential Oil Constituents and Their Mode of Action.

Essential oils (EOs) and plant extracts, rich in beneficial chemical compounds, have diverse applications in medicine, food, cosmetics, and agriculture. This study investigates the antibacterial activity of nine essential oil constituents (EOCs) against Escherichia coli, focusing on the effects of treatment pH and biosynthetic requirements. The impact of EOCs on bacterial inactivation in E. coli strains was examined using both nonselective and selective culture media. Computer-assisted drug design (CADD) methods were employed to identify critical binding sites and predict the main binding modes of ligands to proteins. The EOCs, including citral, α-terpinyl acetate, α-terpineol, and linalool, demonstrated significant bacterial inactivation, particularly under acidic conditions. This study revealed that EOCs have an effect on the presence of sublethal damage to both the cytoplasmic membrane and the outer membrane in Gram-negative bacteria. Adding penicillin G to the repair medium prevents the recovery of sublethal injuries in E. coli treated with α-terpinyl acetate, α-terpineol, linalool, and citral, indicating that peptidoglycan synthesis is essential for recovering from these injuries. However, penicillin G did not hinder the recovery process of most sublethally injured cells treated with the other assessed EOCs. Molecular docking studies revealed the favorable binding interactions of α-terpinyl acetate, α-terpineol, linalool, and citral with the β-lactamase enzyme Toho-1, indicating their potential as effective antibacterial agents. The findings suggest that EOCs could serve as viable alternatives to synthetic preservatives, offering new strategies for combating antibiotic-resistant bacteria.

A comprehensive review of antimicrobial peptides: Mechanisms, classifications and designations

Antimicrobial peptides (AMPs) are a group of alkaline poly-peptide compounds that have antibacterial activity and are produced by insects. This research examines three key aspects of antimicrobial peptides (AMPs): their mechanism of action, categorization, and designation. Antimicrobial peptides have a wide range of antimicrobial action, with a significant number of them being naturally occurring peptides. Consequently, they are increasingly being recognized as promising candidates for therapeutic applications. Antimicrobial peptides can be categorized into many categories based on their structural characteristics and origin. The field of computer-assisted peptide design integrates computer-aided design technology with the process of drug creation, so leveraging its inherent benefits and offering a rational and efficient theoretical framework for the design of peptides. The identification of novel classes of antibiotics is a promising approach for addressing the issue of antibiotic resistance. Antimicrobial peptides possess significant potential for application within the pharmaceutical sector due to their notable antibacterial efficacy, extensive range of antibacterial activity, diverse structural characteristics, and extensive array of options. Moreover, these peptides have a reduced likelihood of inducing resistance mutations in target strains. Currently, a number of poly-peptide antibiotics are being subjected to preclinical feasibility investigations. One of these antibiotics, magainins, has progressed to the phase III clinical trial stage.

The role of 3- D printing technologies

Digital fabrication technology, often known as 3D printing or additive manufacturing, constructs tangible items by incrementally adding materials based on a geometric model. 3D printing technology is a rapidly advancing technology. Currently, 3D printing finds extensive use worldwide. The agricultural, healthcare, automobile, locomotive, and aviation sectors are increasingly utilising 3D printing technology for mass customisation and manufacturing of various open-source designs. 3D printing technology enables the sequential addition of material layers to create an item directly from a computer-assisted design (CAD) model. This article provides an overview of several kinds of 3D printing methods, their applications, and the materials used in the manufacturing business.Additive manufacturing, 3D Printing, Manufacturing industry

Role of Artificial Intelligence in Pharmaceutical Drug Development

: One of the most popular sectors in the tech and healthcare industries right now is artificial intelligence. In the search and development of new drugs, artificial intelligence is essential. Drug design using computer-assisted design (CADD) has supplanted the traditional approach. Artificial intelligence is assisting businesses in the development of new drugs in a faster, more affordable, and more efficient manner, saving money and manpower in the process of creating new drug molecules to treat any disease. Quantitative structure-activity relationship (QSAR) analysis, activity scoring, in silico testing, biomarker development, and mode of action identification are all aided by artificial intelligence. It is revolutionizing these sectors by swiftly identifying potential drug candidates, efficiently conducting clinical trials, and customizing patient care. AI optimizes drug manufacturing processes, augments safety monitoring, and streamlines market analysis. In clinical trials, AI streamlines patient recruitment and ensures more precise trial designs, leading to faster and more efficient research. AI empowers personalized medicine by tailoring treatment plans and drug dosages to individual patient characteristics. AI also optimizes pharmaceutical manufacturing processes, amplifies safety monitoring by analyzing real-time data for adverse events, and supports market analysis and sales strategies. AI in the pharmaceutical industry is a multifaceted tool. Artificial Intelligence (AI) has the potential to streamline complex pharmaceutical regulatory matters. Regulatory processes like audits and dossier completion can be automated with AI tools.

Computational Simulation Study of Potential Inhibition of c-Met Kinase Receptor by Phenoxy pyridine Derivatives: Based on QSAR, Molecular Docking, Molecular Dynamics.

The mesenchymal-epithelial transition factor (c-Met) is a tyrosine kinase receptor protein, and excessive cell transformation can lead to cancer. Therefore, there is an urgent need to develop novel receptor tyrosine kinase inhibitors by inhibiting the activity of c-Met protein. In this study, 41 compounds are selected from the reported literature, and the interactions between phenoxy pyridine derivatives and tumor-associated proteins are systematically investigated using a series of computer-assisted drug design (CADD) methods, aiming to predict potential c-Met inhibitors with high activity. The Topomer CoMFA (q2=0.620, R2=0.837) and HQSAR (q2=0.684, R2=0.877) models demonstrate a high level of robustness. Further internal and external validation assessments show high applicability and accuracy. Based on the results of the Topomer CoMFA model, structural fragments with higher contribution values are identified and randomly combined using a fragment splice technique, result in a total of 20 compounds with predicted activities higher than the template molecules. Molecular docking results show that these compounds have good interactions and van der Waals forces with the target proteins. The results of molecular dynamics and ADMET predictions indicate that compounds Y4, Y5, and Y14 have potential as c-Met inhibitors. Among them, compound Y14 exhibits superior stability with a binding free energy of -165.18 KJ/mol. These studies provide a reference for the future design and development of novel compounds with c-Met inhibitory activity.

Using a three-dimensional natural head position precise recording and transferring device to translate the natural head position into a 3-dimensional virtual patient: A dental technique

As computer-assisted surgical design becomes increasingly popular in maxillofacial surgery, the integration of the natural head position (NHP) of a 3-dimensional virtual patient has become a primary problem that orthognathic surgeons have to solve during virtual surgical planning. The present technique describes a way of transferring the horizon orientation of the NHP into a computer-aided design software program with a recently developed NHP recording and transferring device (Patent No. ZL202110992198.6 China). The device can record NHP using 5 marked points which can be visualized radiographically.

Digital Technology-Assisted "Z" Osteotomy lower limb corrective procedures.

Digital technology is a transformative product of the information age. z-osteotomy is a surgical procedure that corrects limb angulation and lengthens shortening deformities within a 40 mm difference in limb length.The purpose of this study is to Introduce the surgical technique of digitally assisted "Z" osteotomy for correction of angular and length deformities of the lower limbs and investigating its clinical efficacy. A retrospective study was conducted on five patients with multiplanar angular deformities of the lower extremity combined with limb shortening(n=5). The objective of the study was to assess the effectiveness of computer-assisted preoperative design planning and 3D-printed surgical guide fabrication in guiding precise orthopedic procedures. The study compared various parameters, including femoral or tibial cross-sections, coronal and sagittal deformities, limb length, modified Barthel Index, and post-operative complications. Five patients were granted 17.20±6.83 months of follow-up after surgery, with adequate correction of lower limb deformity, significant improvement in postoperative self-care ability improved Barthel index 90±3.08 points (P<0.05). One patient experienced postoperative wound pain at 3 months, which subsequently diminished significantly by the 4-month follow-up assessment., four cases had no complications. The new surgical method of digital technology-assisted "Z" osteotomy for correction of complex deformities of the lower limbs has remarkable clinical results, can accurately correct multi-planar angular deformities and realize limb lengthening at the same time, being safe and reliable.

Targeting Oral Cancer: In Silico Docking Studies of Phytochemicals on Oncogenic Molecular Markers.

Molecular docking is a key tool in structural molecular biology and computer-assisted drug design. Oral carcinogenesis is a complex, multistep process in which genetic events within signal transduction pathways governing normal cellular physiology are quantitatively or qualitatively altered. There are various molecular targets like Cyclin D and PI3k- alpha Ras Binding Domain receptor protein involved in the pathogenesis of Oral Squamous Cell Carcinoma. The aim of the study is to demonstrate the computer aided drug design to identify a potent natural molecule for targeting cyclin D4 and PI3K RAS binding protein. Target selection (Cyclin D1 and PI3K-alpha Ras Binding Domain receptor) was done and structures were derived from protein data bank. Ligands (Apigenin, Chrysoeriol and Luteolin) selection was done and structure derived. Final docking was performed by Autodock. From the docking results it can be seen that luteolin has the highest binding energy (-5.45) with the Cyclin D receptor molecule followed by Chrysoeriol (-4.99) and Apigenin (-4.96). The binding energies of the ligands against PI3K-alpha Ras Binding Domain receptors were Apigenin (-4.51), Chrysoeriol (-4.6) and Luteolin (-4.56). The study concludes that all the three selected ligands possess high binding energy with both the target proteins involved in carcinogenesis with highest binding energy possessed by Luteolin against the Cyclin D receptor and by Chrysoeriol against PI3K-RAS binding protein. Thus their activity can be utilized to derive potential Anti-cancer therapeutic drugs.

3D-printed short-span hybrid composite implant-supported restorations fabricated through tilting stereolithography: A retrospective clinical study on 85 patients with 1 year of follow-up

PurposeTo report the clinical results obtained with fixed short-span (single crowns [SCs] and fixed partial prostheses [FPPs]) implant-supported hybrid composite restorations fabricated through tilting stereolithography (TSLA). MethodsThis retrospective clinical study included 85 patients who had been restored with 95 fixed short-span implant-supported hybrid composite (Irix Max®, DWS Systems) restorations (70 SCs and 25 FPPs up to three units) fabricated with TSLA. The full-digital model-free workflow was based on intraoral implant scanning, computer-assisted design (CAD) and 3D printing using TSLA (Dfab®, DWS Systems). The primary outcomes were the marginal adaptation, the quality of the occlusal and interproximal contact points, and the chromatic integration of the restorations, assessed independently by two experienced operators (a prosthodontist and a periodontist). A score from 1 to 5 (with 5 as the highest value, 4 for satisfactory quality, 3 for acceptable quality, and 2 and 1 as the lowest values, expressing unsatisfactory quality) was assigned by each operator to each restoration at delivery. The secondary outcomes were the survival and success of the restorations at the 1-year follow-up. The restoration was defined as successful in the absence of any complications throughout the follow-up period. A statistical analysis was conducted. ResultsFor the quality of the marginal closure and occlusal and interproximal contact points, the 3D-printed hybrid composite restorations scored highly; the aesthetic integration was satisfactory. One year after placement, all restorations survived, with a low incidence (4.2 % overall, 5.7 % SCs) of complications (two abutment screw loosenings, two decementation of the restorations, and one upper portion of the hybrid abutment decemented from the titanium base), for a success rate of 95.8 %. ConclusionsWithin the limits of this study (retrospective design, follow-up limited to 1 year from the delivery, and only cemented restorations included) fixed short-span implant-supported hybrid composite crowns and bridges fabricated through TSLA were clinically precise, presenting a low incidence of complications at 1 year. Statement of clinical relevanceThe use of TSLA printing technology can open new perspectives for the treatment of small edentulous gaps with definitive implant-supported prosthetic restorations.

Flexural Strength of Different Monolithic Computer-Assisted Design and Computer-Assisted Manufacturing Ceramic Materials Upon Accelerated Aging.

The durability of ceramic is crucial, which is probably influenced by aging. This study evaluated the effect of aging on flexural strength of different ceramics. One-hundred twenty ceramic discs (Ø 12 mm, 1.5 mm thickness) were prepared from zirconia-reinforced lithium silicate (ZLS, C), lithium disilicate (LS2, E), precolored yttria-stabilized tetragonal zirconia polycrystalline (Y-TZP, Ip), and customized color Y-TZP (Ic). Samples were randomly divided into two groups for accelerated aging (A) between 5 and 55°C water baths, 30-second immersing time each, for 10,000 cycles, and nonaged group (N), serving as control. Biaxial flexural strength (σ) was evaluated utilizing the piston-on-three-balls at 0.5 mm/min speed. Analysis of variance and Tukey comparisons were determined for significant differences (α = 0.05). Weibull analysis was applied for survival probability, Weibull modulus (m), and characteristic strength (σo). Microstructures were evaluated with scanning electron microscopy and X-ray diffraction (XRD). The highest σ and σo were seen for IcN, followed by IcA, IpN, IpA, EN, CA, CN, and EA, respectively. CN showed the highest m, while EA showed the lowest m. Significant differences of σ for each ceramic were indicated (p < 0.05). Aging caused a significant difference in σ (p < 0.05). XRD showed t→m phase transformation of Ip and Ic after aging. Aging affected strength of ceramics. Comparable strength between LS2 and ZLS was evidenced, but both were less strength than Y-TZP either aging or non-aging. Comparable strength between precolored Y-TZP and customized color Y-TZP was indicated. Better resisting aging deterioration of Y-TZP than LS2 and ZLS is suggested for fabrication restorative reconstruction.

Computer-assisted semi-rational design enhanced the enzymatic activity and protein stability of Proteinase K in calcium-free conditions

Wild-type Proteinase K binds to two Ca2+ ions, which play an important role in regulating enzymaticactivity and maintaining protein stability. Therefore, a predetermined concentration of Ca2+ must be added during the use of Proteinase K, which increases its commercial cost. Herein, we addressed this challenge using a computational strategy to engineer a Proteinase K mutant that does not require Ca2+ and exhibits high enzymatic activity and protein stability. In the absence of Ca2+, the best mutant, MT24 (S17W–S176N-D260F), displayed an activity approximately 9.2-fold higher than that of wild-type Proteinase K. It also exhibited excellent protein stability, retaining 56.2 % of its enzymatic activity after storage at 4 °C for 5 days. The residual enzymatic activity was 65-fold higher than that of the wild-type Proteinase K under the same storage conditions. Structural analysis and molecular dynamics simulations suggest that the introduction of new hydrogen bond and π-π stacking at the Ca2+ binding sites due to the mutation may be the reasons for the increased enzymatic activity and stability of MT24.

InVADo: Interactive Visual Analysis of Molecular Docking Data.

Molecular docking is a key technique in various fields like structural biology, medicinal chemistry, and biotechnology. It is widely used for virtual screening during drug discovery, computer-assisted drug design, and protein engineering. A general molecular docking process consists of the target and ligand selection, their preparation, and the docking process itself, followed by the evaluation of the results. However, the most commonly used docking software provides no or very basic evaluation possibilities. Scripting and external molecular viewers are often used, which are not designed for an efficient analysis of docking results. Therefore, we developed InVADo, a comprehensive interactive visual analysis tool for large docking data. It consists of multiple linked 2D and 3D views. It filters and spatially clusters the data, and enriches it with post-docking analysis results of protein-ligand interactions and functional groups, to enable well-founded decision-making. In an exemplary case study, domain experts confirmed that InVADo facilitates and accelerates the analysis workflow. They rated it as a convenient, comprehensive, and feature-rich tool, especially useful for virtual screening.

Analysis of Major and Minor Pedicles in Flap Perfusion by Computational Fluid Dynamics.

Type 2 muscle flaps are characterized by major and minor pedicles, such that the minor pedicle is unreliable, and the major pedicle is a requirement for the success of the flap. The role of the minor pedicle, beyond the decreased caliber and decreased vascular territory in comparison to the major pedicle, is poorly understood. We sought to model the fluid dynamics of a model flap containing a major and minor pedicle to understand differences between the pedicles and the implications on perfusion. We first generated a computer-assisted design model of a type 2 flap with a major and minor pedicle. We then performed computational fluid dynamics to analyze velocities and flow within the pedicles and flap. In our investigation, we found that the flow velocity within the major pedicle was higher than the minor pedicle, indicative of decreased resistance to flow. Concomitantly, we found decreased pressures within the major pedicle, reflecting decreasing resistance to flow. Interestingly, we found increased kinematic viscosity in flap areas supplied by the minor pedicle, suggesting decreased flow rates and increased resistance. We identified that the major pedicle has increased flow velocity, decreased resistance, and decreased kinematic viscosity, suggesting its dominance in maintaining flap perfusion. Our study also identifies computational fluid dynamics as a powerful tool in studying flap perfusion dynamics.

Computer-assisted design of CGC catalysts for ethylene/1-octene copolymerization: A combined DFT and artificial neural network approach

High temperature solution polymerization of ethylene/1-octene is the main means to produce polyolefin elastomer (POE), one of the most important polyolefin materials, and the metallocene catalysts with high-efficiency are the key to achieve POE production. However, there remains a deficiency in a universal approach for creating catalysts for ethylene/1-octene copolymerization. In this document, we outlined a method for designing catalysts for ethylene/1-octene copolymerization by combining density functional theory (DFT) with an artificial neural network (ANN) was proposed. By optimizing the structure and computing electronically a sequence of constrained geometry catalysts (CGC) by DFT, descriptors related to steric and electronic descriptors were gathered to create the dataset. After ANN training, an ANN-based model using for predicting catalyst activity with high R2 value was optimized, and a class of novel highly efficient CGC have been successfully designed. Furthermore, an exploration was conducted into how the structure of catalysts correlates with their performance. The electronic properties of the catalysts were found to have more significantly effect on the catalytic performance than the steric properties. In addition, the effect of the β-site substitution of the cyclopentadienyl group on the catalytic activity of predicted CGC was studied and discussed. The groups with ring-structure, especially with conjugate system, were proved to possess a good promoting effect on the catalytic activity.