Application of the process-based teaching based on SPARK case database in the practice teaching of radiology in the musculoskeletal system for undergraduate medical students.

BACKGROUND: Process-based teaching is a new education model. SPARK case database is a free medical imaging case database. This manuscript aimed to explore the application of the process-based teaching based on SPARK case database in the practice teaching of radiology in the musculoskeletal system. METHODS: 117 third year medical students were included. They were divided into Group A, B, C and D according to the curriculum arrangement. Group A and B attended the experimental class at the same time, A was the experimental group, B was the control group. Group C and D attended experimental classes at the same time, C was the experimental group, D was the control group. The experimental group used SPARK case database, while the control group used traditional teaching model for learning. The four groups of students were respectively tested after the theoretical class, before the experimental class, after the experimental class, and one week after the experimental class to compare the results. Finally, all students used SPARK case database to study, and were tested one month after the experimental class to compare their differences. RESULTS: The scores after the theoretical class of Group A and B were (100.0 ± 25.4), (101.0 ± 23.8)(t=-0.160, P > 0.05), Group C and D were (94.7 ± 23.7), (92.1 ± 18.6)(t = 0.467, P > 0.05). The scores of Group A and B before and after the experimental class and one week after the experimental class were respectively (84.1 ± 17.4), (72.1 ± 21.3)(t = 2.363, P < 0.05), (107.6 ± 14.3), (102.1 ± 18.0)(t = 1.292, P > 0.05), (89.7 ± 24.3), (66.6 ± 23.2)(t = 3.706, P < 0.05). The scores of Group C and D were (94.0 ± 17.3), (72.8 ± 25.5)(t = 3.755, P < 0.05), (107.3 ± 20.3), (93.1 ± 20.9)(t = 2.652, P < 0.05), (100.3 ± 19.7), (77.2 ± 24.0)(t = 4.039, P < 0.05). The scores of Group A and B for one month after the experimental class were (86.6 ± 28.8), (84.5 ± 24.0)(t = 0.297, P > 0.05), and Group C and D were (95.7 ± 20.3), (91.7 ± 23.0)(t = 0.699, P > 0.05). CONCLUSIONS: The process-based teaching based on SPARK case database could improve the radiology practice ability of the musculoskeletal system of students.

Application of SPARK teaching in acute abdomen radiography teaching for undergraduate medical students.

BACKGROUND: Acute abdomen is a series of acute and severe abdominal diseases commonly encountered in clinic. It is important to strengthen the image teaching of acute abdomen for undergraduates. AIM: This study aimed to explore the application effect of SPARK[sub-speciality (S), problem-based learning (P), assessment (A), report (R) and reading skill (K)] teaching mode in the experimental teaching of acute abdomen for undergraduate medical students. METHODS: We selected a total of 58 third year medical students for observation. The students were divided into experimental group and control group. Among them, 29 students in the experimental group studied in SPARK teaching mode, 29 students in the control group studied in traditional teaching mode. The two groups of students were tested after the theory class, before and after the experimental class, and one week after the experimental class, to compare the application effects of the two teaching modes. After the test one week after the experimental class, the two groups of students jointly adopted SPARK mode to learn, and were tested again one month after the experimental class to compare whether the two groups of students achieved the same results. The total score of all tests was 150. RESULTS: The average scores of the experimental group and the control group after theory class were (69.0 ± 26.4) and (72.1 ± 24.1) respectively, with no statistical difference (t = 0.468, P = 0.642). The average scores of the experimental group before, after and one week after the experimental class were higher than those of the control group. The experimental group was (84.5 ± 23.1), (109.7 ± 23.8), (105.5 ± 31.0) respectively, and the control group was (52.8 ± 15.1), (93.8 ± 17.0), (80.0 ± 22.8) respectively. The differences were statistically significant (t = -6.195, P = 0.00; t = -2.919, P = 0.05; t = -3.569, P = 0.01). The average scores of the experimental group and the control group after one month were (99.0 ± 31.0) and (95.5 ± 25.6) respectively, and there was no significant difference between the two groups (t = -0.462, P = 0.646). CONCLUSIONS: The SPARK teaching mode was helpful for undergraduate medical students to consolidate image foundation, improve image reading skills.

Single-shot multi-view imaging enabled by scattering lens.

Imaging three-dimensional (3D) objects has been realized by methods such as binocular stereo vision and multi-view imaging. These methods, however, needs multiple cameras or multiple shots to get elemental images. In this paper, we develop a single-shot multi-view imaging technique by utilizing the natural randomness of scattering media. By exploiting the memory effect and uncorrelated point spread functions (PSF) among scattering media, we demonstrate that both stereo imaging with large disparity and up to seven-view imaging of a 3D object can be reconstructed from only one speckle pattern by deconvolution. The elemental images are consistent with 3D object projection and images taken by multi-shot imaging. Our technique provides a feasible method to capture multi-view imaging with short acquisition time and easy calibration.

Holographic fabrication of an arrayed one-axis scale grating for a two-probe optical linear encoder.

We present a method for the fabrication of an arrayed one-axis scale grating for a two-probe optical linear encoder using a dual-beam interference lithography (IL) system with a compact diode laser source. We employ a multiple-exposure stitching method to form an arrayed scale grating. This allows a scale grating with small line spacing to be achieved over a large width. This stitched scale grating integrates well with a newly developed two-probe optical encoder, allowing the measurement results to be numerically connected. Since neither the gap width nor the grating phase of the two adjacent gratings must be controlled, the fabrication process is both simplified and made more robust. This flexible and cost-effective fabrication technique can benefit many precision measurement applications. Experiments are carried out to demonstrate the feasibility of this technology.

Altered intrinsic brain activity and connectivity in unaffected parents of individuals with autism spectrum disorder: a resting-state fMRI study.

Objectives: Autism spectrum disorder (ASD) is a juvenile onset neurodevelopmental disorder with social impairment and stereotyped behavior as the main symptoms. Unaffected relatives may also exhibit similar ASD features due to genetic factors. Although previous studies have demonstrated atypical brain morphological features as well as task-state brain function abnormalities in unaffected parents with ASD children, it remains unclear the pattern of brain function in the resting state. Methods: A total of 42 unaffected parents of ASD children (pASD) and 39 age-, sex-, and handedness-matched controls were enrolled. Multiple resting-state fMRI (rsfMRI) analyzing methods were applied, including amplitude of low-frequency fluctuation (ALFF), regional homogeneity (ReHo), degree centrality (DC), and functional connectivity (FC), to reveal the functional abnormalities of unaffected parents in ASD-related brain regions. Spearman Rho correlation analysis between imaging metric values and the severity of ASD traits were evaluated as well. Results: ALFF, ReHo, and DC methods all revealed abnormal brain regions in the pASD group, such as the left medial orbitofrontal cortex (mOFC) and rectal gyrus (ROI-1), bilateral supplementary motor area (ROI-2), right caudate nucleus head and right amygdala/para-hippocampal gyrus (ROI-3). FC decreasing was observed between ROI-1 and right anterior cingulate cortex (ACC), ROI-2, and bilateral precuneus. FC enhancing was observed between ROI-3 and right anterior cerebellar lobe, left medial temporal gyrus, left superior temporal gyrus, left medial frontal gyrus, left precentral gyrus, right postcentral gyrus in pASD. In addition, ALFF values in ROI-1, DC values in ROI-3 were positively correlated with AQ scores in pASD (ρ 1 = 0.298, P 1 = 0.007; ρ 2 = 0.220, P 2 = 0.040), while FC values between ROI-1 and right ACC were negatively correlated with AQ scores (ρ3 = -0.334, P 3 = 0.002). Conclusion: rsfMRI metrics could be used as biomarkers to reveal the underlying neurobiological feature of ASD for unaffected parents.

Non-invasive super-resolution imaging through dynamic scattering media.

Super-resolution imaging has been revolutionizing technical analysis in various fields from biological to physical sciences. However, many objects are hidden by strongly scattering media such as biological tissues that scramble light paths, create speckle patterns and hinder object's visualization, let alone super-resolution imaging. Here, we demonstrate non-invasive super-resolution imaging through scattering media based on a stochastic optical scattering localization imaging (SOSLI) technique. After capturing multiple speckle patterns of photo-switchable point sources, our computational approach utilizes the speckle correlation property of scattering media to retrieve an image with a 100-nm resolution, an eight-fold enhancement compared to the diffraction limit. More importantly, we demonstrate our SOSLI to do non-invasive super-resolution imaging through not only static scattering media, but also dynamic scattering media with strong decorrelation such as biological tissues. Our approach paves the way to non-invasively visualize various samples behind scattering media at nanometer levels of detail.

Modeling and Analysis of vgs Characteristics for Upper-Side and Lower-Side Switches at Turn-on Transients for a 1200V/200A Full-SiC Power Module.

In this work, a 1200V/200A full-SiC half-bridge power module was fabricated for high-power high-frequency application, and the characteristics of gate-source voltage (vgs) at turn-on transient under different output power was investigated via experiments, modeling, and simulation. Also, the comparison of the vgs characteristics between the upper-side and lower-side was conducted. From experiments, the vgs characteristics show negative spike issue and it becomes severe under higher output power conditions. On the other hand, the upper-side and lower-side show different characteristics, namely, the vgs spike of upper-side is superimposed by a 83.3MHz high frequency oscillation during the process of vgs being pulled down, while the vgs spike of lower-side contains no oscillation. The mechanisms behind the influence of output power on the vgs spike characteristics and their difference between the upper-side and lower-side were studied via modeling and simulation. Equivalent RLC (resistance-inductance-capacitance) circuit models were proposed and established for the gate driver loops of the upper-side and lower-side based on the internal structure of the power module. With the help of the proposed models, vgs characteristics of the upper-side and lower-side were simulated and compared with the experimental results. The trend of changes in the vgs pulling-down and oscillation amplitude along with the increasing output power from simulation are consistent with that of the experimental results. In addition, different conditions of gate resistance for the SiC power module are compared. Through the comparison between the experiments and simulations, the validity of the proposed equivalent RLC circuit model and the rationality of the analysis about the mechanisms behind the vgs characteristics at turn-on transient for SiC half-bridge power module are confirmed.

Alterations in volumes and MRI features of amygdala in Chinese autistic preschoolers associated with social and behavioral deficits.

To examine the amygdala volume in 2-5-year-old preschool children with autism and explore the relationship between amygdala volumes based on MRI findings and clinical features. A total of 39 cases with clinically diagnosed autism were collected. The oblique coronal T1 weighted image (T1WI) sequence was used to measure the volume of amygdala and the MRI signals were measured and analyzed. The data were compared to that of 24 age-matched healthy children and correlated to the clinical manifestations. The autism and the control groups were subject to brain scanning in 1 week after Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV) review. The 39 cases, diagnosed with autism, were associated with social and behavioral deficits through clinical observation, physical and neurological examination, and assessments according to DSM IV, and the range of ABC scores in the autism group was 47-124, with an average score of 84.7 ± 24.1. Abnormal MRI signals were found in 19/78 (24.4%) amygdala in the autism group, the amygdala lesions showed punctuate or flaky low signal, slightly low signal, low to iso-signal, slightly high signal, or iso to high-signal intensity on T1 weighted three-dimendional fast low angle shot(T1FL3D) images. The right amygdala volume average was 1.088 ± 0.38 cm3, while that of the left amygdala was 1.04 ± 0.41 cm3, without any statistically significant difference (t = 0.533, p = 0.596) in the autism group. Among the 24 cases in the control group, the right amygdala volume average was 0.754 ± 0.194 cm3, while that of the left amygdala was 0.666 ± 0.252 cm3; the autism group had a significantly larger right and left amygdala volumes as compared to the age-matched typically developing group with a significant positive correlation between age and right amygdala volume (r = 0.406, p = 0.01). The preschool children with autism had significantly larger bilateral amygdala volumes as compared to age-matched typically developing children, the amygdala lesions may show abnormal signal. A relationship between age and right amygdala volume in the preschool children with autism was established.