Haptic Texture Rendering of 2D Image Based on Adaptive Fractional Differential Method

The fractional differential algorithm has a good effect on extracting image textures, but it is usually necessary to select an appropriate fractional differential order for textures of different scales, so we propose a novel approach for haptic texture rendering of two-dimensional (2D) images by using an adaptive fractional differential method. According to the fractional differential operator defined by the Grünvald–Letnikov derivative (G–L) and combined with the characteristics of human vision, we propose an adaptive fractional differential method based on the composite sub-band gradient vector of the sub-image obtained by wavelet decomposition of the image texture. We apply these extraction results to the haptic display system to reconstruct the three-dimensional (3D) texture force filed to render the texture surface of two-dimensional (2D) images. Based on this approach, we carry out the quantitative analysis of the haptic texture rendering of 2D images by using the multi-scale structural similarity (MS-SSIM) and image information entropy. Experimental results show that this method can extract the texture features well and achieve the best texture force file for 2D images

Haptic Texture Rendering of 2D Image Based on Adaptive Fractional Differential Method

The fractional differential algorithm has a good effect on extracting image textures, but it is usually necessary to select an appropriate fractional differential order for textures of different scales, so we propose a novel approach for haptic texture rendering of two-dimensional (2D) images by using an adaptive fractional differential method. According to the fractional differential operator defined by the Grünvald–Letnikov derivative (G–L) and combined with the characteristics of human vision, we propose an adaptive fractional differential method based on the composite sub-band gradient vector of the sub-image obtained by wavelet decomposition of the image texture. We apply these extraction results to the haptic display system to reconstruct the three-dimensional (3D) texture force filed to render the texture surface of two-dimensional (2D) images. Based on this approach, we carry out the quantitative analysis of the haptic texture rendering of 2D images by using the multi-scale structural similarity (MS-SSIM) and image information entropy. Experimental results show that this method can extract the texture features well and achieve the best texture force file for 2D images

Functional connectivity-based signatures of schizophrenia revealed by multiclass pattern analysis of resting-state fMRI from schizophrenic patients and their healthy siblings

<p>Abstract</p> <p>Background</p> <p>Recently, a growing number of neuroimaging studies have begun to investigate the brains of schizophrenic patients and their healthy siblings to identify heritable biomarkers of this complex disorder. The objective of this study was to use multiclass pattern analysis to investigate the inheritable characters of schizophrenia at the individual level, by comparing whole-brain resting-state functional connectivity of patients with schizophrenia to their healthy siblings.</p> <p>Methods</p> <p>Twenty-four schizophrenic patients, twenty-five healthy siblings and twenty-two matched healthy controls underwent the resting-state functional Magnetic Resonance Imaging (rs-fMRI) scanning. A linear support vector machine along with principal component analysis was used to solve the multi-classification problem. By reconstructing the functional connectivities with high discriminative power, three types of functional connectivity-based signatures were identified: (i) state connectivity patterns, which characterize the nature of disruption in the brain network of patients with schizophrenia; (ii) trait connectivity patterns, reflecting shared connectivities of dysfunction in patients with schizophrenia and their healthy siblings, thereby providing a possible neuroendophenotype and revealing the genetic vulnerability to develop schizophrenia; and (iii) compensatory connectivity patterns, which underlie special brain connectivities by which healthy siblings might compensate for an increased genetic risk for developing schizophrenia.</p> <p>Results</p> <p>Our multiclass pattern analysis achieved 62.0% accuracy via leave-one-out cross-validation (p < 0.001). The identified state patterns related to the default mode network, the executive control network and the cerebellum. For the trait patterns, functional connectivities between the cerebellum and the prefrontal lobe, the middle temporal gyrus, the thalamus and the middle temporal poles were identified. Connectivities among the right precuneus, the left middle temporal gyrus, the left angular and the left rectus, as well as connectivities between the cingulate cortex and the left rectus showed higher discriminative power in the compensatory patterns.</p> <p>Conclusions</p> <p>Based on our experimental results, we saw some indication of differences in functional connectivity patterns in the healthy siblings of schizophrenic patients compared to other healthy individuals who have no relations with the patients. Our preliminary investigation suggested that the use of resting-state functional connectivities as classification features to discriminate among schizophrenic patients, their healthy siblings and healthy controls is meaningful.</p

Anti-DR5 mAb Ameliorate Adjuvant Arthritis Rats Through Inducing Synovial Cells Apoptosis

Objective: Study the therapeutic effects and immunoregulatory mechanisms of anti-DR5 mAb on adjuvant arthritis (AA) rats. Methods: AA rats induced by CFA, were treated with anti-DR5 mAb through mainline administration. Effect on the synovial membranes of the tissues was detected by H&E staining. Flow cytometry and MTT assay were used for detecting the induced apoptosis in an in vitro system and TUNEL assay was used for analysis in an in vivo system. The involvement of the apoptotic pathway was further proved by a caspase inhibition assay. Results: Anti-DR5 mAb could induce synovial cell apoptosis in an in vitro system, which was related with the mRNA expression of DR5 on the cell surface. The mRNA expressions of c-myc and bcl-2 were decreased in synovial cells and those of p21, p53, and bax were increased. The protein expressions of caspase-8/3/9, RANKL, JNK2, and c-Jun were raised and that of bcl-2 was decreased. When the caspase inhibitor was added to the synovial cells treated with anti-DR5 mAb, it showed a dose-dependence inhibition effect, indicating that anti-DR5 mAb inducing apoptosis might be through the caspase pathway. Conclusion: This study shows that anti-DR5 mAb can ameliorate arthritic symptoms. The mechanisms of the treatment are related to the increase in synovial cell apoptosis by regulating the mRNA expression of DR5 and apoptosis-related genes, prolonging the duration of the cell cycle by modulation of the mRNA expression of cell cycle-related genes, and the protein expression of the molecules in the caspase pathway and RANKL, JNK2, and c-Jun. Exp Biol Med 234:1468-1476, 2009Scientific Research Foundation of Fujian Province [2007J0116

A proper protocol for routine 18F-FDG uEXPLORER total-body PET/CT scans

Abstract Background Conventional clinical PET scanners typically have an axial field of view (AFOV) of 15–30 cm, resulting in limited coverage and relatively low photon detection efficiency. Taking advantage of the development of long-axial PET/CT, the uEXPLORER PET/CT scanner with an axial coverage of 194 cm increases the effective count rate by approximately 40 times compared to that of conventional PET scanners. Ordered subset expectation maximization (OSEM) is the most widely used iterative algorithm in PET. The major drawback of OSEM is that the iteration process must be stopped before convergence to avoid image degradation due to excessive noise. A new Bayesian penalized-likelihood iterative PET reconstruction, named HYPER iterative, was developed and is now available on the uEXPLORER total-body PET/CT, which incorporates a noise control component by using a penalty function in each iteration and finds the maximum likelihood solution through repeated iterations. To date, its impact on lesion visibility in patients with a full injected dose or half injected dose is unclear. The goal of this study was to determine a proper protocol for routine 18F-FDG uEXPLORER total-body PET/CT scans. Results The uEXPLORER total-body PET/CT images reconstructed using both OSEM and HYPER iterative algorithms of 20 tumour patients were retrospectively reviewed. The quality of the 5 min PET image was excellent (score 5) for all of the dose and reconstruction methods. Using the HYPER iterative method, the PET images reached excellent quality at 1 min with full-dose PET and at 2 min with half-dose PET. The PET image reached a similar excellent quality at 2 min with a full dose and at 3 min with a half dose using OSEM. The noise in the OSEM reconstruction was higher than that in the HYPER iterative. Compared to OSEM, the HYPER iterative had a slightly higher SUVmax and TBR of the lesions for large positive lesions (≥ 2 cm) (SUVmax: up to 9.03% higher in full dose and up to 12.52% higher in half dose; TBR: up to 8.69% higher in full dose and up to 23.39% higher in half dose). For small positive lesions (≤ 10 mm), the HYPER iterative had an obviously higher SUVmax and TBR of the lesions (SUVmax: up to 45.21% higher in full dose and up to 74.96% higher in half dose; TBR: up to 44.91% higher in full dose and up to 93.73% higher in half dose). Conclusions A 1 min scan with a full dose and a 2 min scan with a half dose are optimal for clinical diagnosis using the HYPER iterative and 2 min and 3 min for OSEM. For quantification of the small lesions, HYPER iterative reconstruction is preferred

Targeting the E2F1/Rb/HDAC1 axis with the small molecule HR488B effectively inhibits colorectal cancer growth

Abstract Colorectal cancer (CRC), the third most common cancer worldwide, remains highly lethal as the disease only becomes symptomatic at an advanced stage. Growing evidence suggests that histone deacetylases (HDACs), a group of epigenetic enzymes overexpressed in precancerous lesions of CRC, may represent promising molecular targets for CRC treatment. Histone deacetylase inhibitors (HDACis) have gradually become powerful anti-cancer agents targeting epigenetic modulation and have been widely used in the clinical treatment of hematologic malignancies, while only few studies on the benefit of HDACis in the treatment of CRC. In the present study, we designed a series of small-molecule Thiazole-based HDACis, among which HR488B bound to HDAC1 with a high affinity and exerted effective anti-CRC activity both in vitro and in vivo. Moreover, we revealed that HR488B specifically suppressed the growth of CRC cells by inducing cell cycle G0/G1 arrest and apoptosis via causing mitochondrial dysfunction, reactive oxygen species (ROS) generation, and DNA damage accumulation. Importantly, we noticed that HR488B significantly decreased the expression of the E2F transcription factor 1 (E2F1), which was crucial for the inhibitory effect of HR488B on CRC. Mechanistically, HR488B obviously decreased the phosphorylation level of the retinoblastoma protein (Rb), and subsequently prevented the release of E2F1 from the E2F1/Rb/HDAC1 complex, which ultimately suppressed the growth of CRC cells. Overall, our study suggests that HR488B, a novel and efficient HDAC1 inhibitor, may be a potential candidate for CRC therapy in the future. Furthermore, targeting the E2F1/Rb/HDAC1 axis with HR488B provides a promising therapeutic avenue for CRC

Opposite effective connectivity in the posterior cingulate and medial prefrontal cortex between first-episode schizophrenic patients with suicide risk and healthy controls.

OBJECTIVE: The schizophrenic patients with high suicide risk are characterized by depression, better cognitive function, and prominent positive symptoms. However, the neurobiological basis of suicide attempts in schizophrenia is not clear. The suicide in schizophrenia is implicated in the defects in emotional process and decision-making, which are associated with prefrontal-cingulate circuit. In order to explore the possible neurobiological basis of suicide in schizophrenia, we investigated the correlation of prefrontal-cingulate circuit with suicide risk in schizophrenia via dynamic casual modelling. METHOD: Participants were 33 first-episode schizophrenic patients comprising of a high suicide risk group (N = 14) and a low suicide risk group (N = 19). A comparison group of healthy controls (N = 15) were matched for age, gender and education. N-back tasking functional magnetic resonance imaging data was collected. RESULTS: Compared with healthy controls group, the two patients groups showed decreased task-related suppression during 2-back task state versus baseline state in the left posterior cingulate and medial prefrontal cortex; the hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex existed in both schizophrenic patients groups, but hypo-connectivity in the opposite direction only existed in the schizophrenic patients group with high suicide risk. CONCLUSIONS: The hyper-connectivity from the left posterior cingulate cortex to the left medial prefrontal cortex may suggest that the abnormal effective connectivity was associated with risk for schizophrenia. The hypo-connectivity in the opposite direction may represent a possible correlate of increased vulnerability to suicide attempt