Efficacy of a Virtual 3D Simulation-Based Digital Training Module for Building Dental Technology Students' Long-Term Competency in Removable Partial Denture Design: Prospective Cohort Study

Background

Removable partial denture (RPD) design is crucial to long-term success in dental treatment, but shortcomings in RPD design training and competency acquisition among dental students have persisted for decades. Digital production is increasing in prevalence in stomatology, and a digital RPD (D-RPD) module, under the framework of the certified Objective Manipulative Skill Examination of Dental Technicians (OMEDT) system reported in our previous work, may improve on existing RPD training models for students.

Objective

We aimed to determine the efficacy of a virtual 3D simulation-based progressive digital training module for RPD design compared to traditional training.

Methods

We developed a prospective cohort study including dental technology students at the Stomatology College of Chongqing Medical University. Cohort 1 received traditional RPD design training (7 wk). Cohort 2 received D-RPD module training based on text and 2D sketches (7 wk). Cohort 3 received D-RPD module pilot training based on text and 2D sketches (4 wk) and continued to receive training based on 3D virtual casts of real patients (3 wk). RPD design tests based on virtual casts were conducted at 1 month and 1 year after training. We collected RPD design scores and the time spent to perform each assessment.

Results

We collected the RPD design scores and the time spent to perform each assessment at 1 month and 1 year after training. The study recruited 109 students, including 58 (53.2%) female and 51 male (56.8%) students. Cohort 1 scored the lowest and cohort 3 scored the highest in both tests (cohorts 1-3 at 1 mo: mean score 65.8, SD 21.5; mean score 81.9, SD 6.88; and mean score 85.3, SD 8.55, respectively; P<.001; cohorts 1-3 at 1 y: mean score 60.3, SD 16.7; mean score 75.5, SD 3.90; and mean score 90.9, SD 4.3, respectively; P<.001). The difference between cohorts in the time spent was not statistically significant at 1 month (cohorts 1-3: mean 2407.8, SD 1370.3 s; mean 1835.0, SD 1329.2 s; and mean 1790.3, SD 1195.5 s, respectively; P=.06) but was statistically significant at 1 year (cohorts 1-3: mean 2049.16, SD 1099.0 s; mean 1857.33, SD 587.39 s; and mean 2524.3, SD 566.37 s, respectively; P<.001). Intracohort comparisons indicated that the differences in scores at 1 month and 1 year were not statistically significant for cohort 1 (95% CI -2.1 to 13.0; P=.16), while cohort 3 obtained significantly higher scores 1 year later (95% CI 2.5-8.7; P=.001), and cohort 2 obtained significantly lower scores 1 year later (95% CI -8.8 to -3.9; P<.001).

Conclusions

Cohort 3 obtained the highest score at both time points with retention of competency at 1 year, indicating that progressive D-RPD training including virtual 3D simulation facilitated improved competency in RPD design. The adoption of D-RPD training may benefit learning outcomes.

Modelling enzyme inhibition toxicity of ionic liquid from molecular structure via convolutional neural network model

Deep learning (DL) methods further promote the development of quantitative structure-activity/property relationship (QSAR/QSPR) models by dealing with complex relationships between data. An acetylcholinesterase inhibitory toxicity model of ionic liquids (ILs) was established using a convolution neural network (CNN) combined with support vector machine (SVM), random forest (RF) and multilayer perceptron (MLP). A CNN model was proposed for feature self-learning and extraction of ILs. By comparing with the model results through feature engineering (FE), the model regression results based on the CNN model for feature extraction have been substantially improved. The results showed that all six models (FE-SVM, FE-RF, FE-MLP, CNN-SVM, CNN-RF, and CNN-MLP) had good prediction accuracy, but the results based on the CNN model were better. The hyperparameters of six models were optimized by grid search and the 10-fold cross validation. Compared with the existing models in the literature, the model performance has been further improved. The model could be used as an intelligent tool to guide the design or screening of low-toxicity ILs.

IS IT MEANINGFUL FOR SERUM MYOGLOBIN IN PATIENTS WITH COVID-19 DECREASED?

More than 3 years since cases were first reported, the COVID-19 pandemic remains an acute global emergency. As of April 12, the number of confirmed deaths worldwide was 6,897,025. Since January 8, 2023, based on the evaluation of the virus mutation, prevention, and control situation, according to the Infectious Diseases Prevention and Control Law, COVID-19 disease has been under Category B management in China. The number of COVID-19 cases in Chinese hospitals nationwide peaked (1.625 million) on January 5, 2023, and then decreased continually to 248,000 on January 23, 2023, with an 84.8% reduction from the peak. During the national COVID-19 pandemic in January 2023, we found that serum myoglobin reduced below the reference interval in 956 patients with COVID-19 who presented to the emergency department of our hospital from January 1 to January 31, 2023. So far, no articles specifically reporting the decrease of serum myoglobin in patients with COVID-19 have been retrieved. These 956 patients with low serum myoglobin were identified from 1142 COVID-19 patients who came to the emergency department of our hospital with symptoms of palpitations or chest tightness or chest pain. All 956 patients visited the hospital more than 2 weeks after the first symptoms appeared. The patient's initial symptoms were fever or cough but resolved before they arrived in the emergency department. There were 358 males and 598 females, aged from 14 to 90 years. Electrocardiogram showed no myocardial damage. Chest CT showed no signs of acute pulmonary infection. Cardiac enzymes and blood cell analysis were performed. The reference interval of serum myoglobin in our hospital is 28.0-72.0 ng/ml in males and 25.0-58.0 ng/ml in females. Patient data were obtained from a review of the electronic medical record system. What is the significance of serum myoglobin falling below the reference interval in patients with COVID-19? So far, no reports have been found in the literature. It may have the following implications: 1. Of cardiac biomarkers, an increase in myoglobin could efficiently predict COVID-19 severity in its early stages. Perhaps a decrease in myoglobin also predicts that COVID-19 patients will not have severe myocardial damage later in the disease. 2. Individuals differ widely in the clinical consequences of SARS-CoV-2 infection, from asymptomatic illness to death. Cong Chen et al. have indirectly demonstrated that SARS-CoV-2 can infect human cardiomyocytes. Most markers in the cardiac enzymes and blood cell analysis of 956 patients did not increase, indicating that the SARS-CoV-2 may not cause myocardial damage in these patients, but cardiac nerve function damage in the later stage of the disease, and then cause palpitations and other symptoms, but not serious cardiovascular disease. 3. It is possible that the virus resides somewhere in the body, such as the nerves of the heart, to cause lasting effects. 4. It may help in the research of drugs to treat COVID-19. The serum myoglobin of 956 patients was significantly decreased without myocardial damage, so we speculated that the symptoms of patients such as heart palpitations were caused by the damage of heart nerves caused by SARS-CoV-2. We further speculated that cardiac nerves were potential drug targets for the treatment of COVID-19. Echocardiography was not performed in 956 patients due to emergency department conditions and time constraints. These 956 patients were not hospitalized or followed up because they did not have myocardial injury or acute pneumonia. The emergency department also did not have adequate laboratory conditions for follow-up studies. We hope that the qualified researchers all over the world will continue to study this.

Ultrafast X-Ray Diffraction Visualization of B1-B2 Phase Transition in KCl under Shock Compression

The classical B1(NaCl)↔B2(CsCl) transitions have been considered as a model for general structural phase transformations, and resolving corresponding phase transition mechanisms under high strain rate shock compression is critical to a fundamental understanding of phase transition dynamics. Here, we use subnanosecond synchrotron x-ray diffraction to visualize the lattice response of single-crystal KCl to planar shock compression. Complete B1-B2 orientation relations are revealed for KCl under shock compression along ⟨100⟩_{B1} and ⟨110⟩_{B1}; the orientation relations and transition mechanisms are anisotropic and can be described with the standard and modified Watanabe-Tokonami-Morimoto model, respectively, both involving interlayer sliding and intralayer ion rearrangement. The current study also establishes a paradigm for investigating solid-solid phase transitions under dynamic extremes with ultrafast synchrotron x-ray diffraction.

LncRNA SNHG8 promotes cell migration and invasion in breast cancer cell through miR-634/ZBTB20 axis

OBJECTIVE

Small nucleolus RNA Host Gene 8 (SNHG8) belongs to a subgroup of long non-coding RNAs. SNHG8 is upregulated in many cancers, such as gastric cancer, liver cancer, and esophageal squamous cell cancer. However, whether SNHG8 is abnormally expressed in breast cancer and its biological functions remain unclear. Therefore, our research intended to determine the expression status of SNHG8 in breast cancer, explore the effects of SNHG8 on the development of breast cancer, and investigate the potential molecular mechanisms in cancer progression.

PATIENTS AND METHODS

The expression levels of SNHG8 were detected in tissue samples and cell lines via qRT-PCR. The effects of SNHG8 on viability of breast cancer cells were detected via CCK-8, EdU, transwell, and flow cytometry analyses.

RESULTS

qRT-PCR results showed that the expression level of SNHG8 was significantly upregulated in tumor tissues and cell lines. Gene functional studies showed that the downregulation of the expression level of SNHG8 significantly inhibited the breast cancer cells migration and invasion, and induced apoptosis. Meanwhile, we found that SNHG8 served as an inhibitor of miR-634 in tumor tissues. SNHG8 may participate in the malignancy of breast cancer by sponging the miR-634 to increase the expression level of ZBTB20.

CONCLUSIONS

The SNHG8-miR-634-ZBTB20 pathway may be a potential target for the treatment of breast cancers.

Multiscale measurements with adjustable x-ray spot size for in situ imaging and diffraction

A large field of view is normally desired for synchrotron x-ray imaging, while a small x-ray spot size is required for x-ray diffraction. A multiscale measurement system with an adjustable x-ray spot size is developed to accommodate different spot size requirements for in situ phase-contrast imaging and diffraction. The centers of a diffraction scintillator with a through-hole and an imaging scintillator are collinear with the x-ray beam. With the proof-of-principle experiments on a magnesium alloy under uniaxial tension, we demonstrate the feasibility of the multiscale measurement system for full azimuthal range diffraction measurements with improved resolution and large field of view strain field measurements via x-ray digital image correlation.

Corneal sub-basal whorl-like nerve plexus: a landmark for early and follow-up evaluation in transthyretin familial amyloid polyneuropathy

BACKGROUND AND PURPOSE

Small-fiber nerves are the first to be involved in transthyretin familial amyloid polyneuropathy (TTR-FAP) patients. In vivo corneal confocal microscopy (CCM) is a noninvasive technique to detect small-fiber polyneuropathy (SFN) by quantifying corneal nerve morphology. The characteristic whorl-like pattern of the corneal nerve provides a static landmark for observation. We aimed to evaluate whether CCM images of the whorl-like plexus can sensitively evaluate and monitor disease progression in FAP patients.

METHODS

Fifteen FAP patients and 15 controls underwent neurological evaluation and CCM observation. Corneal nerve fiber length (CNFL), corneal nerve fiber density (CNFD), corneal nerve branch density (CNBD) detected by conventional method and inferior whorl length (IWL), inferior whorl fiber density (IWFD), and inferior whorl branch density (IWBD) were compared in controls and patients. The Langerhans cell (LC) density in each image was calculated.

RESULTS

All CCM parameters were significantly reduced with disease progression. Preclinical patients had significantly lower IWL (P = 0.008) than age-matched controls. IWL (P = 0.006), CNFL (P = 0.005), CNBD (P = 0.008), and CNFD (P = 0.014) were significantly lower in early-phase patients. LC density was significantly increased around the central whorl in early-phase patients and was relatively lower in progressive patients. Both IWL and CNFL correlated with the severity of neuropathy, and IWL was more significantly reduced. The area under the receiver operating characteristic (ROC) curve for FAP with CNFL and IWL was 88.0% (95% CI, 70.9%-96.9%) and 89.3% (95% CI, 72.6%-97.6%), respectively, exceeding other parameters.

CONCLUSIONS

IWL is a more sensitive surrogate to detect preclinical SFN in FAP and can best discriminate patients from controls. The clustering of immature LCs at the inferior whorl area might reflect the inflammatory response of small-fiber nerves at the early stage.

MicroRNA-374b inhibits migration and invasion of glioma cells by targeting EGFR

OBJECTIVE

To investigate the expression level of microRNA-374b in glioma tissues and its influence on the invasive ability of glioma cells. Meanwhile, the regulatory mechanism of microRNA-374b in glioma was also explored.

PATIENTS AND METHODS

The expression level of microRNA-374b in 32 glioma tissues and para-cancerous tissues were detected by quantitative Real-time polymerase chain reaction (qRT-PCR). The relationship between microRNA-374b expression and clinical indicators of glioma was analyzed. Meanwhile, the expression of microRNA-374b in glioma cells was verified by qRT-PCR as well. Subsequently, microRNA-374b over-expression model was constructed in glioma cell lines, including U251 and U87. Next, the effect of microRNA-374b on cellular biological functions was analyzed using cell counting kit-8 (CCK-8) assay, Wound healing test and transwell invasion assay, respectively. Finally, the relationship between miRNA and epidermal growth factor receptor (EGFR) was explored.

RESULTS

QRT-PCR results showed that the expression level of microRNA-374b in glioma was significantly lower than that of adjacent tissues, and the difference was statistically significant. Compared with patients with higher expression of microRNA-374b, the occurrence rate of lymph node or distant metastasis was significantly higher in those with lower microRNA-374b expression. In addition, compared with NC group, the proliferation, invasion and migration abilities of cells in microRNA-374b mimics group was significantly decreased. Subsequently, results demonstrated that the expression of EGFR was significantly increased in glioma cells and tissues, which was negatively correlated with microRNA-374b expression. Subsequent cell recovery experiment indicated that microRNA-374b and EGFR had a mutual regulation and could affect the malignant progression of glioma all together.

CONCLUSIONS

MicroRNA-374b could inhibit the invasion and migration of glioma by regulating EGFR. Moreover, the expression of microRNA-374b was significantly associated with lymph node metastasis, distant metastasis and poor prognosis.

MiR-3662 suppresses cell growth, invasion and glucose metabolism by targeting HK2 in hepatocellular carcinoma cells

Hepatocellular carcinoma (HCC) is one of the most common malignancies with a rising incidence around the world. MicroRNAs (miRNAs) have been reported to play essential roles in the progression of HCC. However, the precise mechanism of miR-3662 in the HCC process remains poorly understood. This study was aimed to determine the regulatory network of miR-3662 and hexokinase 2 (HK2) in HCC. Quantitative real-time polymerase chain reaction (qRT-PCR) was performed to detect miR-3662 expression. Cell proliferation and invasion were measured by Cell Counting Kit-8 (CCK-8) assay and Transwell assay, respectively. Glucose consumption and lactate production assays were used to detect glucose metabolism activity in HCC cells. The potential binding sites between miR-3662 and HK2 were predicted by TargetScan online software and the relationship between miR-3662 and HK2 was verified by luciferase report assay. The protein expression of HK2 was measured by western blot analysis. A xenograft tumor model was established to confirm the role of miR-3662 and HK2 in vivo. miR-3662 expression was downregulated in HCC tissues and cells, and it was reduced in hypoxia-induced HCC cells in a time-dependent manner. Overexpression of miR-3662 or knockdown of HK2 inhibited cell proliferation, invasion, and glucose metabolism in HCC cells, which could be reversed by upregulating HK2. Besides, HK2 was a direct target of miR-3662 in HCC cells, and hypoxia upregulated the expression of HK2. In addition, the upregulation of HK2 could abolish miR-3662 overexpression-induced inhibitory effects on tumor growth and glucose metabolism in vivo.

[Effects of maslinic acid on isoproterenol-induced myocardial fibrosis in mice]

Objective: To investigate the effect of maslinic acid (MA) on isoproterenol (ISO)-induced myocardial fibrosis in mice. Methods: ISO was used to induce myocardial fibrosis in adult male C57BL/6 mice, and MA was administered for two weeks to detect the effects of MA on cardiac function and fibrosis. Molecular changes of fibrosis markers and signaling pathways were detected by RT-PCR and western blotting. Phosphate buffer saline (PBS), PBS+SB203580 (p38 MAPK inhibitor), PBS+MA, ISO, ISO+SB203580, ISO+MA were added to the primary cultured rat fibroblasts. Cells were collected after 48 h for subsequent detection. Results: In this study, the mouse model of myocardial fibrosis was successfully established. The left ventricular faction shortening (FS) and maximum rate of rise and maximum rate of fall of pressure in left ventricular chamber (±dp/dt) of the ISO+MA group were significantly higher than those of the ISO group ((35.1±1.8)% vs (28.5±2.6)%, (7 256±153) mmHg/s vs (6 402±240) mmHg/s, (7 156±163) mmHg/s vs (6 319±219) mmHg/s, all P<0.05). The levels of interstitial and perivascular collagen deposition in the ISO+MA group were higher than those in the ISO group (P<0.05), the relative mRNA levels of COL-1, COL-3 and TGF-β in the ISO+MA group were significantly lower than those in the ISO group, with the relative expression levels of 1.70±0.24 vs 3.69±0.34, 1.72±0.56 vs 4.84±0.82, 1.52±0.19 vs 2.64±0.29, respectively (all P<0.05). The phosphorylation levels of p38 MAPK, Smad3 and protein expression level of TGF-β1 in ISO+MA group were lower than those in ISO group (relative expression levels were 1.67±0.35 vs 2.61±0.58, 1.68±0.23 vs 2.52±0.19,1.56±0.15 vs 2.48±0.26, respectively, all P<0.05). The results of in vitro cell experiments showed that the mRNA levels of COL-1, COL-3 and TGF-β in the SB203580 and MA groups were significantly lower than those in the ISO group (relative expression levels were 2.25±0.51, 2.16±0.48 vs 5.29±1.21; 1.58±0.34, 1.69±0.29 vs 4.97±1.32; 1.41±0.31, 1.55±0.38 vs 3.53±0.56, respectively, all P<0.05). The phosphorylation levels of p38 MAPK and Smad3 in the SB203580 MA groups was significantly lower than those in the ISO group, and the protein expression level of TGF-β1 was lower than that in the ISO group (1.81±0.18, 1.77±0.16 vs 2.56±0.32; 1.85±0.21, 1.81±0.17 vs 2.48±0.37; 1.84±0.24, 1.72±0.17 vs 2.52±0.29, all P<0.05). Conclusion: Maslinic acid can inhibit the phosphorylation of p38 MAPK, thereby preventing the canonical TGF-β1/Smads fibrosis signaling pathway to achieve an anti-fibrosis role.

Molecular analysis and clinical diversity of distal hereditary motor neuropathy

BACKGROUND AND PURPOSE

Distal hereditary motor neuropathies (dHMNs) are a clinically and genetically heterogeneous group of disorders. The purpose of this study was to identify the genetic distribution of dHMNs in a large cohort of Chinese patients and provide insight into the underlying common pathophysiology of dHMNs.

METHODS

Multi-gene panel testing or whole-exome sequencing was performed in 70 index patients with clinically diagnosed dHMN between January 2007 and December 2018. The clinical features, Charcot-Marie-Tooth (CMT) neuropathy scores and electrophysiological data at diagnosis were recorded.

RESULTS

Twenty-four causative mutations were identified in 70 index patients with dHMN (34.3%). Mutation in the HSPB1 gene was the most common cause of dHMN. Some CMT genes (MPZ, SH3TC2, GDAP1) were found to be related to dHMN with minor sensory involvement. Patients with a dHMN-plus phenotype (distal motor neuropathy and additional neurological deficits) carried variants in genes related to hereditary spastic paraplegia, amyotrophic lateral sclerosis and spinal muscular atrophy (FUS, KIF5A, KIF1B, ZFYVE26, DNAJB2).

CONCLUSIONS

Comprehensive genetic testing of dHMN patients allows for identification of the pathogenic mutation in one-third of cases. Pure motor neuropathies and motor neuropathies with minor sensory involvement share many genes with CMT disease. Causes for dHMN-plus phenotypes overlap with motor neuron disease.

Charge inhomogeneity of carbon

Charge distribution on every atom of carbon matter in four dimension forms (cluster, fullerene, atomistic carbon chain, nanotube, graphene, surface and solid) was investigated by the first-principles calculation. It is found that the charge distribution in most of these materials is inhomogeneous, even in one certain solid phase. We found that if one atom in carbon has different surrounding environment from another one nearby, they always have electron transfer, that is, they have different charge. In round C₁₀ ring, C₂₄ and C₆₀ fullerenes, charge is zero, while charge is not zero in pentagon C₁₀ ring, C₃₀ and C₇₀ fullerenes. At the ends of atomistic chains, nanotube or on the edges of graphenes, carbon atoms have larger positive or negative charge, while almost zero in the central parts. Charge is zero in diamond and graphite, while it is not zero in the high pressure solid phase hexagonite or on some carbon surfaces. The non-zero charge in carbon possibly means its non-zero valence.

3D Printing of Large Areas of Highly Ordered Submicron Patterns for Modulating Cell Behavior

Fabricating large areas of geometrically complex and precisely controlled topographies is required for the studies of cell behavior on patterned surfaces. Direct laser writing (DLW) is an advanced 3D-fabrication technique, which facilitates the manufacturing of structures within various scales (from a few hundred nanometers to millimeters). However, this method requires improvements in the accuracy and reproducibility of the submicron and nanoscale features that are printed over a large area. Here, we present a scheme to both improve the uniformity of the printed submicron patterns and decrease the printing time. The effects of various processing parameters (e.g., laser power and writing field) on the dimensions and uniformity of submicron pillars as well as on their Young's modulus and surface wettability were assessed. Decreasing the writing field to 33 × 33 μm2 significantly improved the uniformity of submicron pillars that were printed over an area of 4 mm2 in a single-step process. Preosteoblast cells (MC3T3-E1) were used to assess the cytocompatibility of the used material (IP-L780 resin) with a focus on cell morphology, cell proliferation, cytoskeletal organization, and the elastic modulus of the cells. The cells cultured for 2 days on the submicron pillars showed a polarized shape and a higher Young's modulus of the area corresponding to the nucleus relative to those cultured on flat surfaces. Taken together, the results of the current study clearly show that the submicron patterns created using DLW are both cytocompatible and could modulate the morphology and mechanical properties of cells. This work paves the way for direct printing of submicron features with controlled Young's moduli over large areas in a single-step process, which is necessary for systematically studying how such patterns modulate cellular functions.

Capture Deformation Twinning in Mg during Shock Compression with Ultrafast Synchrotron X-Ray Diffraction

Deformation twinning plays a vital role in accommodating plastic deformation of hexagonal-close-packed (hcp) metals, but its mechanisms are still unsettled under high strain rate shock compression. Here we investigate deformation twinning in shock-compressed Mg as a typical hcp metal with in situ, ultrafast synchrotron x-ray diffraction. Extension twinning occurs upon shock compression along ⟨112[over ¯]0⟩ and ⟨101[over ¯]0⟩, but only upon release for loading along ⟨0001⟩. Such deformation mechanisms are a result of the polarity of deformation twinning, which depends on directionality and relative magnitude of resolved shear stress and may be common for Mg and its alloys in a wide range of strain rates.

A robotic Intelligent Towing Tank for learning complex fluid-structure dynamics

We describe the development of the Intelligent Towing Tank, an automated experimental facility guided by active learning to conduct a sequence of vortex-induced vibration (VIV) experiments, wherein the parameters of each next experiment are selected by minimizing suitable acquisition functions of quantified uncertainties. This constitutes a potential paradigm shift in conducting experimental research, where robots, computers, and humans collaborate to accelerate discovery and to search expeditiously and effectively large parametric spaces that are impracticable with the traditional approach of sequential hypothesis testing and subsequent train-and-error execution. We describe how our research parallels efforts in other fields, providing an orders-of-magnitude reduction in the number of experiments required to explore and map the complex hydrodynamic mechanisms governing the fluid-elastic instabilities and resulting nonlinear VIV responses. We show the effectiveness of the methodology of "explore-and-exploit" in parametric spaces of high dimensions, which are intractable with traditional approaches of systematic parametric variation in experimentation. We envision that this active learning approach to experimental research can be used across disciplines and potentially lead to physical insights and a new generation of models in multi-input/multi-output nonlinear systems.