ARTICLE | doi:10.20944/preprints202308.0377.v1
Subject: Medicine And Pharmacology, Dentistry And Oral Surgery Keywords: 3D printing; additive manufacturing; dental education; educational models; root canal therapy; ledge; endodontics
Online: 4 August 2023 (08:23:56 CEST)
Ledge formation presents a significant challenge in endodontic treatment. Yet, there is still a lack of educational tooth models for hands-on practice. This study aimed to create and evaluate a tooth model for ledge management practice. A natural tooth with curved roots was collected for scientific use under ethics committee approval. Following initial root canal preparation, the tooth was scanned using micro-computed tomography (μCT) and 3D reconstructed. A K-file, created via computer-aided design (CAD), was partly inserted into the root canal wall of the 3D-reconstructed tooth. By subtracting the K-file from the tooth, a tooth model with a root canal ledge was produced. The models were then 3D printed for a hands-on workshop. A seven-item Likert scale questionnaire was administered to 20 postgraduate students and 10 endodontists to assess the model's quality and training effectiveness. The feedback from both students and experts was positive, with no statistically significant differences found between the two groups (p > 0.05). This novel tooth model is expected to address the existing gap in endodontic education and provide benefits for dental practitioners in future applications.
ARTICLE | doi:10.20944/preprints202311.1403.v1
Subject: Environmental And Earth Sciences, Remote Sensing Keywords: oilfield deformation; MSBAS-InSAR; the Qaidam Basin; geophysical models
Online: 22 November 2023 (07:32:43 CET)
Time series ground deformation monitoring and reservoir parameter inversion are crucial for the dynamic assessment of oilfield resources and sustainable exploitation in an oilfield. As one of the regions with the richest oil reserves in China, the oilfield areas in the western Qaidam Basin are selected as a typical study area. Firstly, we used SAR images collected by the Sentinel-1A satellite from January 2021 to December 2022 and applied the Multidimensional Small Baseline Subset (MSBAS) method to obtain vertical and east-west deformation measurements. On this basis, a nonlinear Bayesian inversion method was applied to model the shallow reservoir in a series of complex deformation areas, based on a single-source model and a multi-source model, respectively. As a result, the ground deformation monitoring results obtained by long time series InSAR clearly reflect the uneven ground deformation caused by the oil extraction and water injection operation process. There is slight subsidence in the Huatugou oilfield, while significant uplift deformation occurred in the Ganchaigou oilfield and the Youshashan oilfield, with a maximum uplift rate of 48 mm/year. Further analysis indicates that the introduction of the 2D deformation field helps to improve the robustness of oilfield reservoir parameter inversion. Moreover, the dual-source model is more suitable than the single-source model for inverting complex deformation reservoir parameters. This study not only fills the blank of InSAR deformation monitoring for the oilfields in the western Qaidam Basin but also provides a theoretical reference for model and method selection of reservoir parameter inversion in other oilfields.
ARTICLE | doi:10.20944/preprints202107.0134.v2
Subject: Medicine And Pharmacology, Neuroscience And Neurology Keywords: Diffusion Magnetic Resonance Imaging; White Matter; Fractional anisotropy; Multi-centre; Reproducibility; Imaging artefacts; Ageing
Online: 6 September 2021 (13:20:18 CEST)
In clinical diagnostics and longitudinal studies, the reproducibility of MRI assessments is of high importance in order to detect pathological changes, but developments in MRI hard- and software often outrun extended periods of data acquisition and analysis. This could potentially introduce artefactual changes or mask pathological alterations. However, if and how changes of MRI hardware, scanning protocols or preprocessing software affect complex neuroimaging outcomes from e.g. diffusion weighted imaging (DWI) remains largely understudied. We therefore compared DWI outcomes and artefact severity of 121 healthy participants (age range 19-54 years) who underwent two matched DWI protocols (Siemens product and Center for Magnetic Resonance Research sequence) at two sites (Siemens 3T Magnetom Verio and Skyrafit). After different preprocessing steps, fractional anisotropy (FA) and mean diffusivity (MD) maps,obtained by tensor fitting, were processed with tract-based spatial statistics (TBSS). Inter-scanner and inter-sequence variability of skeletonised FA values reached up to 5% and differed largely in magnitude and direction across the brain. Skeletonised MD values differed up to 14% between scanners. We here demonstrate that DTI outcome measures strongly depend on imaging site and software, and that these biases vary between brain regions. These regionally inhomogeneous biases may exceed and considerably confound physiological effects such as ageing, highlighting the need to harmonise data acquisition and analysis. Future studies thus need to implement novel strategies to augment neuroimaging data reliability and replicability.
Subject: Biology And Life Sciences, Biochemistry And Molecular Biology Keywords: tetraodon palembangensis; chromosome-level genome; genomic annotation; gene family
Online: 31 August 2020 (04:28:47 CEST)
The humpback puffer, Tetraodon palembangensis, also known as Pao palembangensis, is a species of poisonous freshwater pufferfish mainly distributed in Southeast Asia (Thailand, Laos, Malaysia and Indonesia). Despite interesting biological features, such as its very inactive nature, tetrodotoxin production and body expansion mechanisms, molecular research on the humpback puffer is still rare because of the lack of a high-quality reference genome. Here, we reported a first chromosome-level genome assembly of an adult humpback puffer, of which the genome size is 362 Mb with ~1.78 Mb contig N50 and ~15.8 Mb scaffold N50s. Based on the genome, ~61.5Mb (18.11%) repeat sequences were also identified, and totally 19,925 genes were annotated, 99.20% of which could be predicted with function using protein-coding function databases. Finally, a phylogenetic tree was constructed with single-copy gene families from ten teleost fishes. The humpback puffer genome will be a valuable genomic resource to illustrate possible mechanisms of tetrodotoxin synthesis and tolerance, providing clues for future detailed studies of biological toxins.
REVIEW | doi:10.20944/preprints201812.0156.v1
Subject: Biology And Life Sciences, Ecology, Evolution, Behavior And Systematics Keywords: Marine microorganisms, marine fungi, algae, marine plants, marine invertebrates, marine vertebrates, genome, metagenome
Online: 12 December 2018 (15:44:09 CET)
With the continuing development of sequencing technology, genomics has been applied in a variety of biological research areas. In particular, the application of genomics to marine species, which boast a high diversity, promises great scientific and industrial potential. Significant progress has been made in marine genomics especially over the past few years. Consequently, BGI, leveraging its prominent contributions in genomics research, established BGI-Qingdao, an institute specifically aimed at exploring marine genomics. In order to accelerate marine genomics research and related applications, BGI-Qingdao initiated the International Conference on Genomics of the Ocean (ICG-Ocean) to develop international collaborations and establish a focused and coherent global research plan. Last year, the first ICG-Ocean conference was held in Qingdao, China, during which 47 scientists in marine genomics from all over the world reported on their research progress to an audience of about 300 attendees. This year, we would like to build on that success, drafting a report on marine genomics to draw global attention to marine genomics. We summarized the recent progress, proposed future directions, and we would like to enable additional profound insights on marine genomics. Similar to the annual report on plant and fungal research by Kew Gardens, and the White Paper of ethical issues on experimental animals, we hope our first report on marine genomics can provide some useful insights for researchers, funding agencies as well as industry, and that future versions will expand upon the foundation established here in both breadth and depth of knowledge.This report summarizes the recent progress in marine genomics in six parts including: marine microorganisms, marine fungi, marine algae and plants, marine invertebrates, marine vertebrates and genomics-based applications.