Computer Modeling Software Research Articles

Assessment of Anisotropic Acoustic Properties in Additively Manufactured Materials: Experimental, Computational, and Deep Learning Approaches.

The influence of acoustic anisotropy on ultrasonic testing reliability poses a challenge in evaluating products from additive technologies (AT). This study investigates how elasticity constants of anisotropic materials affect defect signal amplitudes in AT products. Experimental measurements on AT samples were conducted to determine elasticity constants. Using Computational Modeling and Simulation Software (CIVA), simulations explored echo signal changes across ultrasound propagation directions. The parameters A13 (the ratio between the velocities of ultrasonic transverse waves with vertical and horizontal polarizations at a 45-degree angle to the growth direction), A3 (the ratio for waves at a 90-degree angle), and Ag (the modulus of the difference between A13 and A3) were derived from wave velocity relationships and used to characterize acoustic anisotropy. Comparative analysis revealed a strong correlation (0.97) between the proposed anisotropy coefficient Ag and the amplitude changes. Threshold values of Ag were introduced to classify anisotropic materials based on observed amplitude changes in defect echo signals. In addition, a method leveraging deep learning to predict Ag based on data from other anisotropy constants through genetic algorithm (GA)-optimized neural network (NN) architectures is proposed, offering an approach that can reduce the computational costs associated with calculating such constants.

AutoMolDesigner for Antibiotic Discovery: An AI-Based Open-Source Software for Automated Design of Small-Molecule Antibiotics.

Discovery of small-molecule antibiotics with novel chemotypes serves as one of the essential strategies to address antibiotic resistance. Although a considerable number of computational tools committed to molecular design have been reported, there is a deficit in holistic and efficient tools specifically developed for small-molecule antibiotic discovery. To address this issue, we report AutoMolDesigner, a computational modeling software dedicated to small-molecule antibiotic design. It is a generalized framework comprising two functional modules, i.e., generative-deep-learning-enabled molecular generation and automated machine-learning-based antibacterial activity/property prediction, wherein individually trained models and curated datasets are out-of-the-box for whole-cell-based antibiotic screening and design. It is open-source, thus allowing for the incorporation of new features for flexible use. Unlike most software programs based on Linux and command lines, this application equipped with a Qt-based graphical user interface can be run on personal computers with multiple operating systems, making it much easier to use for experimental scientists. The software and related materials are freely available at GitHub (https://github.com/taoshen99/AutoMolDesigner) and Zenodo (https://zenodo.org/record/10097899).

The use of Computational Modeling for Simulation and Comparison of Digital Elevation Models in Northwest Fluminense. Case Study: Pomba River and Paraíba do Sul River

Purpose: The work proposes the location, simulation and comparison of Digital Elevation Models (DEM) in a section where the Pomba River and the Paraíba do Sul River meet, located in the northwest of the state of Rio de Janeiro, a region known for the reproduction of some species of fish threatened with extinction. Methods: Searches for DEMs in the region were carried out on a free website, where a total of 10 DEMs were found. Several hydraulic simulations were carried out using computer modeling software called Iber, to verify the veracity and coherence of the data available. Results and conclusion: After simulating all DEMs, it was found that the DEM that best represented the study region, with greater coherence in topography and hydraulics, was the DEM provided by Copernicus with a 5m lowering. Research implications: Hydraulic simulations are fundamental for preventing dangerous situations for society as a whole. Together with the studies carried out through simulations, it is possible to analyze their hydraulic and topographic coherence for the flow of rivers and also their floodability for urbanized/dry regions. Originality/value: Verification of the coherence of data provided by the Open Topography website using Iber software, as a method of preventing hydraulic disasters (floods).

Evaluation of Physicochemical and Geoelectrical Parameters of Soil and Water around Electronic Dumpsites in Selected Locations of Aba, Nigeria

Electronic waste can be harmful to human health as it contains some heavy metals which alter the wellbeing of people. Aba being a commercial city in Southeastern Nigeria is lying on permeable soil. The indiscriminate disposal of these items makes it expedient for the investigation to be carried out by studying the characteristics of the soil and groundwater quality in order to ascertain the concentration of some of these heavy metals which pollute the water. Resistivities of the soil were determined by employing the vertical electrical sounding method and using some appropriate computer modeling software such as ip2win, surfer12, grapher 8, etc. to interpret the geoelectric sections. Water samples were collected from twenty different locations (BH1 to BH20 and leachate site), then, analyzed using atomic absorption spectrophotometer which revealed the concentration levels of some elements including heavy metals and some compounds such as Al (4.5–40.26 mg/L), As (0.0–3.78 mg/L), Cd (0.0–3.78 mg/L), Cr (0.0–0.543 mg/L), Cu (0.0–21.54 mg/L), Fe (0.15–9.27 mg/L), Pb (0.0–5.604 mg/L), Hg (0.0–2.688 mg/L), Ni (0.0–0.504 mg/L), Ag (0.04–1.2 mg/L), Zn (0.0004–5.2 mg/L), CN (0.84–2.63 mg/L), NH3 (0.004–2.74 mg/L), PO4 (0.3–8.4 mg/L), SO4 (0.0–35 mg/L), etc. The soil resistivities range from 500 Ωm to 1000 Ωm and the depth to water is between 20 m to 40 m. The results revealed that water level is very close to the ground surface and hence, the groundwater is prone to pollution. Also, the percentage concentration of some of the heavy metals is high, which points to a serious threat to life.

Novel Pyrazinoindolones As Amyloid‐Beta Aggregation Inhibitors

AbstractBackgroundAlzheimer’s disease (AD) is a devastating neurodegenerative condition which primarily affects the elderly population. One of hallmarks of AD is the accumulation of protein aggregates known as amyloid‐beta (Aβ) that promotes neurotoxicity and cognitive decline. Recent discoveries in the field led to the accelerated market approval of anti‐Aβ antibodies aducanumab and lecanemab. These are exciting discoveries. However, considering the cost and patient compliance issues with these biological therapies, discovering novel anti‐Aβ therapies that are based on small molecules is highly desirable due to several advantages over biological therapies including the ease of oral administration, reduced cost involved in bulk manufacturing and better stability on storage.MethodA library of novel pyrazino[1,2‐a]indole‐1(2H)‐one derivatives were designed using the computational modeling software Discovery Studio Structure‐Based‐Design (Biovia Inc, San Diego USA). Then synthetic chemistry protocols were optimized to prepare small molecule library and were characterized by 1H and 13C NMR and Liquid Chromatography Mass Spectrometry studies. The anti‐Aβ activity of these novel molecules toward Aβ40 aggregation was evaluated by fluorescence spectroscopy using the thioflavin‐T based aggregation kinetic studies. In addition, the online web tool SwissADME was used to calculate the physicochemical properties of pyrazino[1,2‐a]indole‐1(2H)‐one derivatives to assess their drug‐likeness, blood‐brain barrier permeability and pharmacokinetics.ResultA novel library of pyrazino[1,2‐a]indole‐1(2H)‐one derivatives were prepared by optimizing a four step or two step synthesis protocol starting from either phenylhydrazine or indole‐2‐carboxylic acid to afford pyrazino[1,2‐a]indole‐1(2H)‐one derivatives 5a–f. In the Aβ40 (5 μM) aggregation kinetics assay, they exhibited 14‐59% inhibition when tested at a range of concentrations (1, 5, 10 and 25 μM), demonstrating their anti‐Aβ properties. Their physicochemical properties suggest their drug‐likeness.ConclusionStructure‐activity relationship studies demonstrate that the fused tricyclic pyrazino[1,2‐a]indole‐1(2H)‐one is a suitable template to i) develop novel chemical tools to study and understand the mechanisms of Aβ40 aggregation and ii) discover novel small molecules as potential therapies for AD.

SAT165 A Novel Mutation In The HNF4α Gene (C.691C>T, P.arg231trp) Likely To Be Pathogenic For Maturity Onset Diabetes Of The Young Type 1 Presenting With Hyperinsulinemic Hypoglycemia In An Infant

Abstract Disclosure: A. Rodriguez: None. S. Sastry: None. W. Chemaitilly: None. N. Gurtunca: None. Background: Maturity Onset Diabetes of the Young type 1 (MODY 1) is a monogenic form of diabetes mellitus caused by a defective HNF4α gene, resulting in reduced insulin secretion and diabetes in early adolescence and young adulthood. MODY 1 is also known to be associated with increased insulin secretion during fetal, neonatal and childhood periods with consequences that range from fetal macrosomia to persistent hyperinsulinism. Traditionally, HNF4α gene mutations represents 5% of all cases of diazoxide-responsive hyperinsulinism. Clinical Case: A 1 month old male born full term and large for gestational age (birth weight of 4920g) following an uncomplicated pregnancy and delivery developed hypoglycemia soon after birth and required hospital admission on day of life 2 with a serum glucose of 30 mg/dL and an insulin level of 5 uIU/mL. A fasting challenge showed hypoglycemia at 9 hours with a serum glucose of 47 mg/dL and an insulin level of 10.3 uIU/mL confirming hyperinsulinemic hypoglycemia. He was started on diazoxide to which he responded well and was placed on a continuous glucose monitor (CGM). He was originally started on diazoxide 8mg/kg/day that later was decreased to 6.6mg/kg/day due to blood glucoses in the 200’s. He passed the fasting study 5 days after starting diazoxide and went home with the CGM with subsequent dose titration made with guidance from remote data sharing. A neonatal hypoglycemia panel was sent and showed a novel mutation, c.691C>T, p.ARG231Trp in the HNF4α gene classified as a variant of uncertain significance. Computer modeling software suggested that this gene might disrupts the gene structure and function. This variant is present in population databases at a 0.0009% frequency and this missense change has been observed in individuals with clinical features of maturity onset diabetes of the young. Patient’s father carries the same mutation and paternal grandmother carries a diagnosis of type 2 diabetes mellitus. Conclusion: This is a novel mutation that should be considered pathogenic based on this patient’s neonatal presentation and previous literature. This case also presents possible uses of CGM in infants with diazoxide responsive congenital hyperinsulinism in order to decrease burden from monitoring and streamline communication with the medical team Presentation: Saturday, June 17, 2023

Dual-Targeted Therapy in HER2-Overexpressing Breast Cancer with Trastuzumab and Novel Cholesterol-Based Nioplexes Silencing Mcl-1.

The challenge in HER2-overexpressing breast cancer therapy lies in creating an effective target therapy to overcome treatment resistance. Monoclonal antibodies and target gene silencing by siRNA are two potential strategies that have been widely developed for treating HER2-positive breast cancer. The siRNA delivery system is a crucial factor that influences siRNA therapy's success. In this study, lipid-based nanoparticles (cationic niosomes) composed of different cholesterol-based cationic lipids were formulated and characterized for delivering siRNA into HER2-overexpressing breast cancer cells. Niosomes containing a trimethylammonium headgroup showed the highest siRNA delivery efficiency with low toxicity. The myeloid cell leukemia-1 (Mcl-1) siRNA nioplex treatment significantly decreased mRNA expression and breast cancer cell growth. Dual-targeted therapy, consisting of treatment with an Mcl-1 siRNA nioplex and trastuzumab (TZ) solution, noticeably promoted cell-growth inhibition and apoptosis. The synergistic effect of dual therapy was also demonstrated by computer modeling software (CompuSyn version 1.0). These findings suggest that the developed cationic niosomes were effective nanocarriers for siRNA delivery in breast cancer cells. Furthermore, the Mcl-1 nioplex/TZ dual treatment establishes a synergistic outcome that may have the potential to treat HER2-overexpressing breast cancer.

Parametric design of a modular acoustic panel for sound recording space versatility

Increasingly sound recording studios are demanded to host projects of different acoustic needs. However, their sonic character, product of their contents and bulky conventional treatment solutions, usually remains unchanged. This paper reports a modular panel's early-stage design, aimed at providing flexibility to a group of representative recording rooms. The versatility refers to acoustical (absorption and diffusion), practical (volume and weight), and aesthetic aspects. The geometry and materials of the panel were derived parametrically through computer modelling software, by implementing interdependent and adaptable elements to one unit. Existing recording spaces were recreated into computational acoustic models and tested in two states. Simulations of the rooms' acoustical behaviour were run in turn, first with the original treatment, then with the panel replacing the treatment. The design goal was to have minimal differences in Reverberation Time, Early Decay Time, Clarity, Room Frequency Response for every room's two states. Results showed the panel performing better in rooms with larger volume. Overall, the panel matched the original acoustic response and character of the rooms, while providing versatility when compared to traditional acoustic treatment solutions. The development of such a product would allow future studio users fine tune the room's performance according to their needs.

Biomechanical Investigation of the Efficacy of Conventional Bicycle Helmets at Preventing Facial Injury

Many studies indicate that wearing a bicycle helmet significantly reduces the risk of accident-related head injuries. Less is reported, however, about bicycle helmet use, about preventing facial injury. Epidemiological studies typically report incidences of 'head injury,' though rarely categorize head, brain, and facial injuries separately. Studies that do focus on facial injury suggest that helmets do not provide adequate protection. A 3D biofidelic child head form and two conventional bicycle helmets (that is,” open face") were created in MSC ADAMS™ computer modelling and simulation software. Peak force and linear accelerations were measured for a series of head form impact simulations corresponding to an established testing standard and a newly proposed series of tests derived from modified motorcycle standards, incorporating injury thresholds from the facial bone impact tolerance literature. Almost all impact simulations exceeded the threshold for fracture, soft tissue, and dental trauma. An observational study was conducted using MSC ADAMS™ to assess a helmeted headform's face exposure during impact simulations. Helmets failed to reduce face impact exposure, during all simulations, except for perpendicular cheek impacts. International test standards, therefore, require urgent revision to ensure that face protection is included.

An Anatomic Study of the Proximal Tibial Epiphysis With Relevance to Percutaneous Epiphysiodesis Using Transphyseal Screws (PETS).

Percutaneous epiphysiodesis using transphyseal screws (PETS) is a common procedure to correct lower extremity limb-length discrepancies in the pediatric population. A potential complication of this procedure is development of tibial valgus deformity, which may occur secondary to decreased screw purchase in the thinner medial proximal tibial epiphysis. The thickness of the proximal tibial epiphysis has not yet been well quantified, which was the aim of this study. Three-dimensional surface scans of 32 cadaveric proximal tibial epiphyses in specimens aged 3 to 17 years old were obtained and computer modeling software was utilized to measure the thickness of the proximal tibial epiphysis at 20 standardized potential screw insertion points according to a generated 5×4 map. When normalized to the total width of the proximal tibial epiphysis, the lateral side is thicker compared with the medial side. The positions with the greatest thickness are located at the midline in the sagittal plane and 33% of the total physeal width away from the medial and lateral edges in the coronal plane (0.265 and 0.261 normalized thickness, respectively). The proximal tibial epiphysis is particularly thin 25% from the medial edge (normalized thickness range: 0.196 to 0.221). Multiple regression analysis revealed a significant relationship between increasing age and female sex with thinner normalized medial and lateral heights. During PETS, areas for greater screw purchase are located centrally in the sagittal plane and 33% of the total width away from the medial and lateral edges of the proximal tibial epiphysis in the coronal plane. Caution should be taken when inserting screws in the medial 25% of the proximal tibial epiphysis as it is thinner relative to the lateral edge, particularly in females. This study provides quantitative, anatomic data on the thickness of the proximal tibial epiphysis, which can direct screw placement during PETS for correcting limb-length discrepancies. These data may help lessen the risk of developing tibial valgus deformity although future clinical studies are necessary to fully evaluate this possibility.

Advances in Process Modelling and Simulation of Parabolic Trough Power Plants: A Review

The common design of thermal power plants is fundamentally oriented towards achieving a high-process performance, with market demands necessitating enhanced operational stability as a result of ongoing global support for renewable energy sources. Indeed, dynamic simulation represents one useful and cost-effective choice for optimizing the flexibility of parabolic trough power plants (PTPP) in a range of transient operating conditions, such as weather changes, resulting again in variations of the output load as well as varying start-up times. The purpose of this review is to provide an overview of steady-state and dynamic modelling for PTPP design, development, and optimization. This gives us a greater opportunity for a broad understanding of the PTPPs subjected to a variety of irradiance solar constraints. The most important features of the steady-state and their uses are reviewed, and the most important programs used in steady-state modelling are also highlighted. In addition, the start-up process of the plant, thermal storage system capacities and response dynamics (charging and discharging modes), and yearly electricity yield can be analyzed using dynamic modelling. Depending on the dynamic simulation, specific uses can be realized, including control loop optimization, load estimation for critical in-service equipment, and emergency safety assessment of power plants in the event of an outage. Based on this review, a detailed overview of the dynamic simulation of PTPP, and its development and application in various simulation programs, is presented. Here, a survey of computational dynamic modelling software commonly applied for commercial and academic applications is performed, accompanied by various sample models of simulation programs such as APROS, DYNAMICS, DYMOLA, and ASPEN PLUS. The simulation programs generally depend on the conservation equations of mass, momentum, species, and energy. However, for the equation of equilibrium, specific mathematical expressions rely on the basic flow model. The essential flow models involved, together with the basic assumptions, are presented, and are supplemented through a general survey covering popular simulation programs. Various previous research on the dynamic simulation of the PTPP are reviewed and analyzed in this paper. Here, several studies in the literature regarding the dynamic simulation of the PTPP are addressed and analyzed. Specific consideration is given to the studies including model verification, in order to explore the effect of modelling assumptions regarding the simulation outputs.

Mathematical Modeling of the Protective Effect of Ethyl Silicate Gel Coating on Textile Materials under Conditions of Constant or Dynamic Thermal Exposure

The influence of the process of fire-retardant coating on textiles on the degree of fire protection of cotton and blended fabrics is investigated. Physical-chemical properties of impregnated samples of textile materials depending on the composition of ethyl silicate hydrolysates, concentration and content of diammonium hydrogen phosphate on fire resistance of impregnated samples, time of onset destruction and area of charring of samples after fire tests are analyzed. The obtained experimental data showed the need to build a mathematical model of the protective action of the gel coating based on the laws of heat and mass transfer, which under conditions of maximum simplicity and minimal artificiality takes into account the main processes from the external heat flow processes of heat transfer, thermal decomposition, evaporation and removal of mass, as well as to develop algorithms and software for computer modeling of the protective action of such a coating in conditions of constant or dynamic thermal exposure. A mathematical model of fire-retardant action of organosilicon coating on cellulose-containing fiber of fabric threads has been developed. It provides predictive estimates of fire safety parameters of textile materials, based on the level of thermal impact on the surface of the protected material.

An anatomic and 3D study of the development of the proximal humeral physis.

During maturation, the ossification centers of the proximal humerus form a characteristic pattern consisting of a metaphyseal peak and corresponding epiphyseal valley. The surface topographies of the metaphyseal peak and epiphyseal valley are not well described and may have variation with age and structural importance to the pathogenesis of proximal humeral epiphysiolysis. High-resolution 3-dimensional surface scans of 24 cadaveric proximal humeral epiphyses and metaphyses in specimens aged 3 to 18years were obtained. Computer modeling software was used to measure the peak height of the metaphysis and maximal depth of the epiphysis relative to a perpendicular line drawn across the proximal humeral physis. The metaphyseal peak had a mean height of 12.7 ± 1.6mm while the epiphyseal valley had a mean depth of 13.1 ± 2.1mm, both consistently positioned in the posterolateral quadrant. Both the absolute metaphyseal peak height (R2 = 0.536; p < 0.001) and absolute epiphyseal valley depth (R2 = 0.524; p < 0.001) increase with advancing age. Multiple linear regression analysis demonstrated that normalized metaphyseal peak height + sex (adjusted R2 = 0.408; p < 0.002) correlated more with age than normalized epiphyseal valley depth + sex (adjusted R2 = 0.128; p < 0.091). Prominence of the metaphyseal peak and epiphyseal valley both increase with advancing age, with a lower correlation between normalized sizes with age as compared to the absolute sizes, suggesting that these structures stay relatively proportional with growth.

Application of computer modeling software for mining vehicle fleet telemetry monitoring

Application of computer modeling software for mining vehicle fleet telemetry monitoring

Phytochemical, Cytotoxicity, and Antimycobacterial Activity Evaluation of Extracts and Compounds from the Stem Bark of Albizia coriaria Welw ex. Oliver.

Background Albizia coriaria Welw ex. Oliver (Fabaceae) is one of the plants used by herbalists in the East Africa community to prepare herbal remedies for the management of symptoms of TB. Despite its widespread use, the antimycobacterial activity of this plant was uninvestigated and there was contradicting information regarding its cytotoxicity. Methods Cytotoxicity (MTT), antimycobacterial activity (MABA), and phytochemical screening were conducted on crude extracts (hexane, chloroform, acetone, and methanol) of the stem bark of A. coriaria. Gas chromatography-mass spectrometry (GC-MS) followed by Fourier transform infrared (FTIR) spectroscopy was carried out on the acetone and methanol extracts. The binding affinities and descriptors of pharmacokinetics and toxicity of the identified compounds were predicted using computational modelling software. Results The cytotoxic concentrations of all extracts were greater than 1000 μg/mL. The minimum inhibitory concentration of both the acetone and methanol extracts was 1250.0 ± 0.0 μg/mL against M. smegmatis, whereas that against M. tuberculosis was 937.0 ± 442.0 μg/mL and 2500.0 ± 0.0 μg/mL, respectively. Hexane and chloroform extracts were not active against both strains. Alkaloids, triterpenes, flavonoids, tannins, and saponins were the predominant phytochemicals present. GC-MS analysis revealed twenty-eight and nineteen compounds in acetone and methanol extracts, respectively. Among these was hydroquinone, which was previously reported to possess antimycobacterial activity. Seven compounds identified through GC-MS analysis had better binding affinities for the mycobacterial ATPase and polyketide synthase-13 than isoniazid and rifampicin. These compounds also showed variable but promising pharmacokinetic properties with minimum toxicity. Conclusion There are phytochemicals in A. coriaria stem bark with potential antimycobacterial activity and acceptable cytotoxicity, which can be further explored and optimized for the development of novel antitubercular drugs.

Indoor Optimal Design of Building Renovation Environment Space Layout Based on Genetic Algorithm

The design of the buildings should not only meet the requirements of structural safety and functional applicability, but also ensure that the stress of the structural system is reasonable and the amount of materials is as small as possible. And the reasonable and optimal allocation of resources should be realized. The research and application of optimization algorithms for building structures are still relatively scarce. It is difficult to obtain the optimal solution based on genetic algorithm because of the large amount of time-consuming calculation of indoor environment and the complex optimization process of indoor design. In order to realize the optimization design of parametric design combined with architectural physics and structural performance, we must use the current powerful computer platform optimization algorithm, mainly genetic algorithm. Firstly, this paper explores the implementation process of genetic algorithm in parametric design platform and the characteristics of optimization calculation. The experimental model is established based on genetic algorithm, combined with computer intelligent operation platform and modeling software. Combined with EnergyPlus energy consumption simulation engine and daysim daylighting simulation engine, the optimization design process of genetic algorithm optimization is realized through Pareto intelligent solution programming. The optimization design method can quantitatively calculate and evaluate the spatial layout, and provide visual, more accurate and intuitive output results.

Multi-purpose robotic arm control system

The purpose of this work is to create methods and algorithms for the formation of multi-purpose automatic control systems for the robotic arm, as well as to develop specialized software for computer modeling of the developed algorithms on the example of a real robotic arm. The methods of forming multi-purpose automatic motion control systems for various objects are developed, and the features of using a multi-purpose structure for control dynamic objects are studied.

Cross-Sectional Areas and Volumes Occupied by Implants in Simulated Scaphoid Fractures

This study determined the volume of bone replaced by an implant at the proximal and distal poles of simulated scaphoid fractures. We also measured the cross-sectional area of the implant relative to the cross-sectional area of the scaphoid at 2 different simulated fracture locations. Microcomputed tomograhy scans of 7 cadaveric scaphoids were used to create 3-dimensional models in which transverse proximal pole and midwaist fractures were simulated. The volume occupied by 5 commonly used implants and the cross-sectional area occupied at the surface of the fractures was measured using a computer modeling software. For simulated proximal pole fractures, the implants replaced 1.5%-7.4% of the fracture cross-sectional area and 1.2%-6.4% of the proximal fragment bone volume. For midwaist fractures, the implants replaced 1.5%-6.8% of the fracture cross-sectional area and 1.8%-4.6% of the proximal pole volume. Although the different implant designs replaced different areas and volumes, all these differences were small and below 4%. This study provides data that relate to one aspect of fracture healing, specifically, the surface area occupied by 5 different implants in proximal and midwaist scaphoid fractures as well as the volume of bone replaced by the implant. As opposed to the impression provided by 2-dimensional planar imaging, when studied using a 3-dimensional model, the volume and surface area replaced by an implant represent a minimal percentage of scaphoid bone, suggesting a negligible clinical effect.

The development and testing of Thai facial soft tissue thickness data in three-dimensional computerized forensic facial reconstruction.

Forensic facial reconstruction is a useful tool to assist the public in recognizing human remains, leading to positive forensic investigation outcomes. To reproduce a virtual face, facial soft tissue thickness is one of the major guidelines to reach the accuracy and reliability for three-dimensional computerized facial reconstruction, a method that is making a significant contribution to improving forensic investigation and identification. This study aimed to develop a facial soft tissue thickness dataset for a Thai population, and test its reliability in the context of facial reconstruction. Three-dimensional facial reconstruction was conducted on four skulls (2 males and 2 females, with ages ranging between 51 to 60 years). Two main tools of three-dimensional computer animation and modeling software-Blender and Autodesk Maya-were used to rebuild the three-dimensional virtual face. The three-dimensional coordinate (x, y, z) cutaneous landmarks on the mesh templates were aligned homologous to the facial soft tissue thickness markers on the three-dimensional skull model. The final three-dimensional virtual face was compared to the target frontal photograph using face pool comparison. Four three-dimensional virtual faces were matched at low to moderate levels, ranging from 30% to 70% accuracy. These results demonstrate that the facial soft tissue thickness database of a Thai population applied in this study could be useful for three-dimensional computerized facial reconstruction purposes.

An anatomical study defining the safe range of angles in percutaneous iliosacral and transsacral screw fixation.

Percutaneous iliosacral screw fixation and transsacral fixation are challenging procedures requiring extensive knowledge of sacral anatomy to avoid damaging nearby neurovascular structures. Greater knowledge of anatomical screw trajectory and size allowances would be helpful to guide surgical placement. An anatomical study of 40 cadaveric sacra in specimens ages 18-65 was performed. Three-dimensional surface scans were obtained, and computer modeling software was used to simulate a 7.3 mm diameter screw with 1 mm buffer inserted orthogonal to the sacroiliac joint in the pelvic inlet and outlet views. Transsacral screws were also inserted into S1 and S2 vertebrae. For screws orthogonal to the sacroiliac joint, the overall mean screw insertion angle was 4.1° ± 7.5° (range, -18.3° to 22.0°) in the inlet view in the posterior to anterior direction, and 21.7° ± 5.1° (range, 8.2°-36.3°) in the outlet view in the caudal to cranial direction. Before breaching the sacrum, the range of sacral tunnel lengths was between 31.1 and 70.1 mm with a range of diameters between 9.3 and 13.3 mm. Transsacral screws inserted into either the S1 or S2 vertebrae did not breach the sacrum in 40% (16/40) at each level. 30% (12/40) of sacra could not safely accommodate both S1 and S2 transsacral screws. There is an initial screw insertion angle range of -4° to 12° in the inlet view and 16°-27° in the outlet view. There was always adequate size to accept a 7.3 mm or larger screw.