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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
DOE OSTI2023

classLog: Logistic regression for the classification of genetic sequences

Introduction Sequencing and phylogenetic classification have become a common task in human and animal diagnostic laboratories. It is routine to sequence pathogens to identify genetic variations of diagnostic significance and to use these data in realtime genomic contact tracing and surveillance. Under this paradigm, unprecedented volumes of data are generated that require rapid analysis to provide meaningful inference. Methods We present a machine learning logistic regression pipeline that can assign classifications to genetic sequence data. The pipeline implements an intuitive and customizable approach to developing a trained prediction model that runs in linear time complexity, generating accurate output rapidly, even with incomplete data. Our approach was benchmarked against porcine respiratory and reproductive syndrome virus (PRRSv) and swine H1 influenza A virus (IAV) datasets. Trained classifiers were tested against sequences and simulated datasets that artificially degraded sequence quality at 0, 10, 20, 30, and 40%. Results When applied to a poor-quality sequence data, the classifier achieved between >85% to 95% accuracy for the PRRSv and the swine H1 IAV HA dataset and this increased to near perfect accuracy when using the full dataset. The model also identifies amino acid positions used to determine genetic clade identity through a feature selection ranking within the model. These positions can be mapped onto a maximum-likelihood phylogenetic tree, allowing for the inference of clade defining mutations. Discussion Our approach is implemented as a python package with code available at https://github.com/flu-crew/classLog .

Zeller, Michael A.↗
DOE OSTI2022

Training Ultrasound Image Classification Deep-Learning Algorithms for Pneumothorax Detection Using a Synthetic Tissue Phantom Apparatus

Ultrasound (US) imaging is a critical tool in emergency and military medicine because of its portability and immediate nature. However, proper image interpretation requires skill, limiting its utility in remote applications for conditions such as pneumothorax (PTX) which requires rapid intervention. Artificial intelligence has the potential to automate ultrasound image analysis for various pathophysiological conditions. Training models require large data sets and a means of troubleshooting in real-time for ultrasound integration deployment, and they also require large animal models or clinical testing. Here, we detail the development of a dynamic synthetic tissue phantom model for PTX and its use in training image classification algorithms. The model comprises a synthetic gelatin phantom cast in a custom 3D-printed rib mold and a lung mimicking phantom. When compared to PTX images acquired in swine, images from the phantom were similar in both PTX negative and positive mimicking scenarios. We then used a deep learning image classification algorithm, which we previously developed for shrapnel detection, to accurately predict the presence of PTX in swine images by only training on phantom image sets, highlighting the utility for a tissue phantom for AI applications.

Boice, Emily N. (ORCID:0000000171802842)↗
DOE OSTI2023

ASF Vaccine Candidate ASFV-G-ΔI177L Does Not Exhibit Residual Virulence in Long-Term Clinical Studies

African swine fever (ASF) is an important disease in swine currently producing a pandemic affecting pig production worldwide. Except in Vietnam, where two vaccines were recently approved for controlled use in the field, no vaccine is commercially available for disease control. Up to now, the most effective vaccines developed are based on the use of live-attenuated viruses. Most of these promising vaccine candidates were developed by deleting virus genes involved in the process of viral pathogenesis and disease production. Therefore, these vaccine candidates were developed via the genomic modification of parental virus field strains, producing recombinant viruses and reducing or eliminating their residual virulence. In this scenario, it is critical to confirm the absence of any residual virulence in the vaccine candidate. This report describes the assessment of the presence of residual virulence in the ASFV vaccine candidate ASFV-G-ΔI177L in clinical studies conducted under high virus loads and long-term observation periods. The results demonstrated that domestic pigs intramuscularly inoculated with 10 6 HAD 50 of ASFV-G-ΔI177L did not show the presence of any clinical sign associated with ASF when observed daily either 90 or 180 days after vaccination. In addition, necropsies conducted at the end of the experiment confirmed the absence of macroscopic internal lesions associated with the disease. These results corroborate the safety of using ASFV-G-ΔI177L as a vaccine candidate.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2023

Animals Exposed to Leptospira Serogroups Not Included in Bacterins in the United States and Puerto Rico

Leptospirosis is a worldwide zoonotic disease. Pathogenic leptospires colonize the renal tubules and genital tract of animals and are excreted via urine. Transmission occurs via direct contact or through contaminated water or soil. The microscopic agglutination test (MAT) is the gold standard for the serodiagnosis of leptospirosis. The present study aims to evaluate animal exposure to Leptospira in the U.S. and Puerto Rico during the period 2018–2020. The presence of antibodies against pathogenic Leptospira spp. was assessed with the MAT according to the standards of the World Organisation for Animal Health. A total of 568 sera were submitted for diagnostic, surveillance, or import/export testing from the U.S. and Puerto Rico. Seropositivity (≥1:100) was 51.8% (294/568) with agglutinating antibodies found in 115 (39.1%) cattle, 84 (28.6%) exotic animals, 38 (12.9%) horses, 22 (7.5%) goats, 15 (5.1%) dogs, 11 (3.7%) swine, and 9 (3.1%) sheep. The most detected serogroups were Australis, Grippotyphosa, and Ballum. The results showed that animals were exposed to serogroups/serovars not included in commercial bacterins such as Ballum, Bratislava (only in swine vaccine), and Tarassovi. Our findings suggest that more studies should include culture and concomitant genotyping to reduce animal disease and zoonotic risk through efficacious vaccine and diagnostic strategies.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2022

Experimental Senecavirus A Infection of Bovine Cell Lines and Colostrum-Deprived Calves

Senecavirus A (SVA) is a causative agent for vesicular disease in swine, which is clinically indistinguishable from other vesicular diseases of swine including foot-and-mouth disease (FMD). Recently, it was reported that buffalo in Guangdong, China were experiencing clinical symptoms similar to FMD including mouth ulcers and lameness tested positive for SVA. The objective of this study was to determine the susceptibility of cattle (Bos taurus) to SVA infection. Initial in vitro work using the PrimeFlow assay demonstrated that bovine cell lines and peripheral blood mononuclear cells from cattle were susceptible to SVA infection. Subsequently, six colostrum-deprived Holstein calves were challenged with SVA intranasally. No vesicular lesions were observed after challenge. Serum, oral, nasal, and rectal swabs tested for SVA nucleic acid did not support significant viral replication and there was no evidence of seroconversion. Therefore, demonstrating cattle from this study were not susceptible to experimental SVA infection.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2024

Full-Length ASFV B646L Gene Sequencing by Nanopore Offers a Simple and Rapid Approach for Identifying ASFV Genotypes

African swine fever (ASF) is an acute, highly hemorrhagic viral disease in domestic pigs and wild boars. The disease is caused by African swine fever virus, a double stranded DNA virus of the Asfarviridae family. ASF can be classified into 25 different genotypes, based on a 478 bp fragment corresponding to the C-terminal sequence of the B646L gene, which is highly conserved among strains and encodes the major capsid protein p72. The C-terminal end of p72 has been used as a PCR target for quick diagnosis of ASF, and its characterization remains the first approach for epidemiological tracking and identification of the origin of ASF in outbreak investigations. Recently, a new classification of ASF, based on the complete sequence of p72, reduced the 25 genotypes into only six genotypes; therefore, it is necessary to have the capability to sequence the full-length B646L gene (p72) in a rapid manner for quick genotype characterization. Here, we evaluate the use of an amplicon approach targeting the whole B646L gene, coupled with nanopore sequencing in a multiplex format using Flongle flow cells, as an easy, low cost, and rapid method for the characterization and genotyping of ASF in real-time.

Virology↗
NASA NTRS2013

Epidermal Homeostasis and Radiation Responses in a Multiscale Tissue Modeling Framework

The surface of skin is lined with several thin layers of epithelial cells that are maintained throughout life time by a small population of stem cells. High dose radiation exposures could injure and deplete the underlying proliferative cells and induce cutaneous radiation syndrome. In this work we propose a multiscale computational model for skin epidermal dynamics that links phenomena occurring at the subcellular, cellular, and tissue levels of organization, to simulate the experimental data of the radiation response of swine epidermis, which is closely similar to human epidermis. Incorporating experimentally measured histological and cell kinetic parameters, we obtain results of population kinetics and proliferation indexes comparable to observations in unirradiated and acutely irradiated swine experiments. At the sub-cellular level, several recently published Wnt signaling controlled cell-cycle models are applied and the roles of key components and parameters are analyzed. Based on our simulation results, we demonstrate that a moderate increase of proliferation rate for the survival proliferative cells is sufficient to fully repopulate the area denuded by high dose radiation, as long as the integrity of underlying basement membrane is maintained. Our work highlights the importance of considering proliferation kinetics as well as the spatial organization of tissues when conducting in vivo investigations of radiation responses. This integrated model allow us to test the validity of several basic biological rules at the cellular level and sub-cellular mechanisms by qualitatively comparing simulation results with published research, and enhance our understanding of the pathophysiological effects of ionizing radiation on skin.

Hu, Shaowen↗
NASA NTRS1998

Pulmonary blood flow redistribution by increased gravitational force

This study was undertaken to assess the influence of gravity on the distribution of pulmonary blood flow (PBF) using increased inertial force as a perturbation. PBF was studied in unanesthetized swine exposed to -Gx (dorsal-to-ventral direction, prone position), where G is the magnitude of the force of gravity at the surface of the Earth, on the Armstrong Laboratory Centrifuge at Brooks Air Force Base. PBF was measured using 15-micron fluorescent microspheres, a method with markedly enhanced spatial resolution. Each animal was exposed randomly to -1, -2, and -3 Gx. Pulmonary vascular pressures, cardiac output, heart rate, arterial blood gases, and PBF distribution were measured at each G level. Heterogeneity of PBF distribution as measured by the coefficient of variation of PBF distribution increased from 0.38 +/- 0.05 to 0.55 +/- 0.11 to 0.72 +/- 0.16 at -1, -2, and -3 Gx, respectively. At -1 Gx, PBF was greatest in the ventral and cranial and lowest in the dorsal and caudal regions of the lung. With increased -Gx, this gradient was augmented in both directions. Extrapolation of these values to 0 G predicts a slight dorsal (nondependent) region dominance of PBF and a coefficient of variation of 0.22 in microgravity. Analysis of variance revealed that a fixed component (vascular structure) accounted for 81% and nonstructure components (including gravity) accounted for the remaining 19% of the PBF variance across the entire experiment (all 3 gravitational levels). The results are inconsistent with the predictions of the zone model.

NASA Discipline Cardiopulmonary↗
DOE OSTI2023

Deriving spatially explicit direct and indirect interaction networks from animal movement data

Abstract Quantifying spatiotemporally explicit interactions within animal populations facilitates the understanding of social structure and its relationship with ecological processes. Data from animal tracking technologies (Global Positioning Systems [“GPS”]) can circumvent longstanding challenges in the estimation of spatiotemporally explicit interactions, but the discrete nature and coarse temporal resolution of data mean that ephemeral interactions that occur between consecutive GPS locations go undetected. Here, we developed a method to quantify individual and spatial patterns of interaction using continuous‐time movement models (CTMMs) fit to GPS tracking data. We first applied CTMMs to infer the full movement trajectories at an arbitrarily fine temporal scale before estimating interactions, thus allowing inference of interactions occurring between observed GPS locations. Our framework then infers indirect interactions—individuals occurring at the same location, but at different times—while allowing the identification of indirect interactions to vary with ecological context based on CTMM outputs. We assessed the performance of our new method using simulations and illustrated its implementation by deriving disease‐relevant interaction networks for two behaviorally differentiated species, wild pigs ( Sus scrofa ) that can host African Swine Fever and mule deer ( Odocoileus hemionus ) that can host chronic wasting disease. Simulations showed that interactions derived from observed GPS data can be substantially underestimated when temporal resolution of movement data exceeds 30‐min intervals. Empirical application suggested that underestimation occurred in both interaction rates and their spatial distributions. CTMM‐Interaction method, which can introduce uncertainties, recovered majority of true interactions. Our method leverages advances in movement ecology to quantify fine‐scale spatiotemporal interactions between individuals from lower temporal resolution GPS data. It can be leveraged to infer dynamic social networks, transmission potential in disease systems, consumer–resource interactions, information sharing, and beyond. The method also sets the stage for future predictive models linking observed spatiotemporal interaction patterns to environmental drivers.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2019

Nuclear Factor-κB is Activated in Filter-Implanted Vena Cava

Background: Implantation of a retrievable vena cava filter (VCF) is an effective method for preventing pulmonary embolism. Retrieval of filters, however, may be difficult due to intimal hyperplasia and inflammation in the cava wall. The transcription factor nuclear factor-kappaB (NF-κB) plays an important role in regulation of numerous genes participating in the inflammatory and proliferative responses of cells. The present study was to determine whether VCF implantation resulted in activation of NF-κB in the venous neointima. Methods: Filters were placed in vena cava (VC) in four swine for 30 days and then removed. Intimal specimens adhering to the filter struts were analyzed with reference to normal VC tissues. Immunohistochemical analyses were used to assess the NF-κB subunits p65 and p50 and the phosphorylated inhibitor of κB-α (phosphor-IκB-α) in the tissues. NF-κB DNA-binding activity was measured with enzyme-linked immunosorbent assay. Results: As compared to normal VC tissues, the intimal tissues contained higher percentages of cell nucleus-located p65 and p50, and NF-κB DNA-binding activity. Elevated immunoreactivities of p65, p50 and phosphor-IκB-α were also present in the intima. Conclusion: The present study demonstrates for the first time that VCF implantation caused NF-κB activation in neointima. We further demonstrate the activation is at least partly due to phosphorylation of IκB-α. Our data suggest that NF-κB activation would significantly contribute to development of intimal hyperplasia and inflammation in filter-inserted vena cava walls. NF-κB might be a therapeutic target for inhibiting filter-induced neointima and improving filter retrieval.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Robotically Assisted Sonic Therapy (RAST) for Noninvasive Hepatic Ablation in a Porcine Model: Mitigation of Body Wall Damage with a Modified Pulse Sequence

Purpose: Robotically assisted sonic therapy (RAST) is a nonthermal, noninvasive ablation method based on histotripsy. Prior animal studies have demonstrated the ability to create hepatic ablation zones at the focal point of an ultrasound therapy transducer; however, these treatments resulted in thermal damage to the body wall within the path of ultrasound energy delivery. The purpose of this study was to evaluate the efficacy and safety of a pulse sequence intended to mitigate prefocal body wall injury. Materials and Methods: Healthy swine (n = 6) underwent hepatic RAST (VortxRx software version 1.0.1.3, HistoSonics, Ann Arbor MI) in the right hepatic lobe. A 3.0 cm spherical ablation zone was prescribed for each. Following treatment, animals underwent MRI which was utilized for ablation zone measurement, evaluation of prefocal injury, and assessment of complications. Each animal was euthanized, underwent necropsy, and the tissue was processed for histopathologic analysis of the ablation zone and any other sites concerning for injury. Results: No prefocal injury was identified by MRI or necropsy in the body wall or tissues overlying the liver. Ablation zones demonstrated uniform cell destruction, were nearly spherical (sphericity index = 0.988), and corresponded closely to the prescribed size (3.0 × 3.1 × 3.4 cm, p = 0.70, 0.36, and 0.01, respectively). Ablation zones were associated with portal vein (n = 3, one occlusive) and hepatic vein thrombosis (n = 4, one occlusive); however, bile ducts remained patent within ablation zones (n = 2). Conclusions: Hepatic RAST performed with a modified ultrasound pulse sequence in a porcine model can mitigate prefocal body wall injuries while maintaining treatment efficacy. Further study of hepatic RAST appears warranted, particularly in tumor models.

62 RADIOLOGY AND NUCLEAR MEDICINE↗
DOE OSTI2019

Establishment of CRISPR/Cas9-Mediated Knock-in System for Porcine Cells with High Efficiency

Since the birth of clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9, the new genome engineering technology has become a hot topic in the scientific community. However, for swine, the system of pig cells’ homology directed repair (HDR) is generally unstable and costly. Here, we aim to make knock-in of porcine cells more realizable. The Rosa26 locus was chosen for gene editing. Through the optimization of strategy, an efficient sgRNA was selected by TIDE analysis. Correspondingly, a vector system was constructed for gene insertion in pRosa26 locus by homologous recombination. A large percentage of cells whose gene is edited easily result in apoptosis. To improve the positive rate, culturing systems have been optimized. Sequence alignment and nuclear transfer confirmed that we got two knock-in cell lines and transgene primary porcine fetal fibroblasts (PFFs) successfully. Results showed that the gene editing platform we used can obtain genetically modified pig cells stably and efficiently. This system can contribute to pig gene research and production of transgenic pigs.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Increased microbiome diversity at the time of infection is associated with improved growth rates of pigs after co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2)

Porcine reproductive and respiratory syndrome virus (PRRSV) and porcine circovirus type 2 (PCV2) are two of the most important pathogens affecting the swine industry worldwide. Co-infections are common on a global scale, resulting in pork production losses through reducing weight gain and causing respiratory disease in growing pigs. Our initial work demonstrated that the fecal microbiome was associated with clinical outcome of pigs 70 days post-infection (dpi) with PRRSV and PCV2. However, it remained uncertain if microbiome characteristics could predispose response to viral infection. The purpose of this study was to determine if microbiome characteristics present at the time of virus exposure were associated with outcome after co-infection. Using the Lawrence Livermore Microbial Detection Array, we profiled the microbiome in feces prior to infection from pigs identified retrospectively as having high or low growth rates after co-infection. High growth rate pigs had less severe interstitial pneumonia, reduced virus replication, and a significant increase in average daily weight gain throughout the study. At the level of the fecal microbiome, high growth rate pigs had increased microbial diversity on both a family and species level. Shifts in the microbiome composition of high growth rate pigs included reduced Methanobacteriaceae species, increased Ruminococcaceae species, and increased Streptococcaceae species when compared to low growth rate pigs. The results of the study indicate that both microbiome diversity and composition at the time of virus exposure may play a role in the subsequent response of pigs to PRRSV/PCV2 co-infection.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2016

Identification and subcellular localization of porcine deltacoronavirus accessory protein NS6

Porcine deltacoronavirus (PDCoV) is an emerging swine enteric coronavirus. Accessory proteins are genus-specific for coronavirus, and two putative accessory proteins, NS6 and NS7, are predicted to be encoded by PDCoV; however, this remains to be confirmed experimentally. Here, we identified the leader-body junction sites of NS6 subgenomic RNA (sgRNA) and found that the actual transcription regulatory sequence (TRS) utilized by NS6 is non-canonical and is located upstream of the predicted TRS. Using the purified NS6 from an Escherichia coli expression system, we obtained two anti-NS6 monoclonal antibodies that could detect the predicted NS6 in cells infected with PDCoV or transfected with NS6-expressing plasmids. Further studies revealed that NS6 is always localized in the cytoplasm of PDCoV-infected cells, mainly co-localizing with the endoplasmic reticulum (ER) and ER-Golgi intermediate compartments, as well as partially with the Golgi apparatus. Together, our results identify the NS6 sgRNA and demonstrate its expression in PDCoV-infected cells. -- Highlights: •The leader-body fusion site of NS6 sgRNA is identified. •NS6 sgRNA uses a non-canonical transcription regulatory sequence (TRS). •NS6 can be expressed in PDCoV-infected cell. •NS6 predominantly localize to the ER complex and ER-Golgi intermediate compartment.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2017

Kobuvirus VP3 protein restricts the IFN-β-triggered signaling pathway by inhibiting STAT2-IRF9 and STAT2-STAT2 complex formation

Emerged porcine kobuvirus (PKV) has adversely affected the global swine industry since 2008, but the etiological biology of PKV is unclear. Screening PKV-encoded structural and non-structural proteins with a type I IFN-responsive luciferase reporter showed that PKV VP3 protein inhibited the IFN-β-triggered signaling pathway, resulting in the decrease of VSV-GFP replication. QPCR data showed that IFN-β downstream cytokine genes were suppressed without cell-type specificity as well. The results from biochemical experiments indicated that PKV VP3 associated with STAT2 and IRF9, and interfered with the formation of the STAT2-IRF9 and STAT2-STAT2 complex, impairing nuclear translocation of STAT2 and IRF9. Taken together, these data reveal a new mechanism for immune evasion of PKV. - Highlights: •PKV VP3 inhibits the IFN-β-triggered signaling pathway. •VP3 associates with STAT2 and IRF9. •VP3 blocks the STAT2-IRF9 nuclear translocation. •VP3 utilizes a novel strategy for innate immune evasion.

60 APPLIED LIFE SCIENCES↗
DOE OSTI2019

Transcriptomic differences noted in Glaesserella parasuis between growth in broth and on agar

Glaesserella parasuis is the cause of Gla¨sser’s disease in pigs and is a significant contributor to post-weaning mortality in the swine industry. Prevention of G. parasuis disease relies primarily on bacterin vaccines, which have shown good homologous protection and variable heterologous protection. Bacterin production involves large scale growth of the bacteria and proteins produced during the proliferation phase of production become important antigens that stimulate the immune response. In order to evaluate genes activated during G. parasuis growth on different media substrates, the transcriptome of broth and agar grown G. parasuis strain 29755 were sequenced and compared. The transcription of most purported virulence genes were comparable between broth and agar grown G. parasuis; however, four virulence-associated genes, including ompA and vapD, had elevated expression under agar growth, while six virulence-associate genes had elevated expression during broth growth, including several protease genes. Additionally, there were metabolic shifts toward increased protein and lipid production and increased cellular division in broth grown G. parasuis. The results contribute to the understanding of how growth substrate alters gene transcription and protein expression, which may impact vaccine efficacy if immunogens important to the protective immune response are not produced under specific in vitro conditions. While the results of this work are unable to fully elucidate which growth medium presents a transcriptome more representative of in vivo samples or best suited for bacterin production, it forms a foundation that can be used for future comparisons and provides a better understanding of the metabolic differences in broth and agar grown bacteria.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Transiently Transfected Mammalian Cell Cultures: An Adaptable and Effective Platform for Virus-like Particle-Based Vaccines against Foot-and-Mouth Disease Virus

RNA viruses, such as foot-and-mouth disease virus (FMDV), have error-prone replication resulting in the continuous emergence of new viral strains capable of evading current vaccine coverage. Vaccine formulations must be regularly updated, which is both costly and technically challenging for many vaccine platforms. In this report, we describe a plasmid-based virus-like particle (VLP) production platform utilizing transiently transfected mammalian cell cultures that combines both the rapid response adaptability of nucleic-acid-based vaccines with the ability to produce intact capsid epitopes required for immunity. Formulated vaccines which employed this platform conferred complete protection from clinical foot-and-mouth disease in both swine and cattle. This novel platform can be quickly adapted to new viral strains and serotypes through targeted exchanges of only the FMDV capsid polypeptide nucleic acid sequences, from which processed structural capsid proteins are derived. This platform obviates the need for high biocontainment manufacturing facilities to produce inactivated whole-virus vaccines from infected mammalian cell cultures, which requires upstream expansion and downstream concentration of large quantities of live virulent viruses.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

Computer-aided Veress needle guidance using endoscopic optical coherence tomography and convolutional neural networks

During laparoscopic surgery, the Veress needle is commonly used in pneumoperitoneum establishment. Precise placement of the Veress needle is still a challenge for the surgeon. In this study, a computer-aided endoscopic optical coherence tomography (OCT) system was developed to effectively and safely guide Veress needle insertion. This endoscopic system was tested by imaging subcutaneous fat, muscle, abdominal space, and the small intestine from swine samples to simulate the surgical process, including the situation with small intestine injury. Each tissue layer was visualized in OCT images with unique features and subsequently used to develop a system for automatic localization of the Veress needle tip by identifying tissue layers (or spaces) and estimating the needle-to-tissue distance. We used convolutional neural networks (CNNs) in automatic tissue classification and distance estimation. In conclusion, the average testing accuracy in tissue classification was 98.53 ± 0.39%, and the average testing relative error in distance estimation reached 4.42 ± 0.56% (36.09 ± 4.92 μm).

59 BASIC BIOLOGICAL SCIENCES↗