Using unsupervised capsule neural network reveal spatial representations in the human brain.

Humans can extract high-level spatial features from visual signals, but spatial representations in the brain are complex and remain unclear. The unsupervised capsule neural network (U-CapsNet) is sensitive to the spatial location and relationship of the object, contains a special recurrent mechanism and uses a self-supervised generation strategy to represent images, which is similar to the computational principle in the human brain. Therefore, we hypothesized that U-CapsNet can help us understand how the human brain processes spatial information. First, brain activities were studied using functional magnetic resonance imaging during spatial working memory in which participants had to remember the locations of circles for a short time. Then, U-CapsNet served as a computational model of the brain to perform tasks that are identical to those performed by humans. Finally, the representational models were used to compare the U-CapsNet with the brain. The results showed that some human-defined spatial features naturally emerged in the latent space of U-CapsNet. Moreover, representations in U-CapsNet captured the response structure of two types of brain regions during different activity patterns, as well as important factors associated with human behavior. Together, our study not only provides a computationally feasible framework for modeling how the human brain encodes spatial features but also provides insights into the representational format and goals of the human brain.

Surgical Treatment for Type A Aortic Dissection after Endovascular Aortic Repair: A 12-year, Single-Center Study.

OBJECTIVE: This study aims to investigate the clinical manifestations, operative techniques, and outcomes of patients who undergo open repair after thoracic endovascular aortic repair (TEVAR). METHODS: From January 2010 to June 2022, 113 consecutive type A aortic dissection (TAAD) patients underwent secondary open operation after TEVAR at our institution, and the median interval from primary intervention to open surgery was 12 (1.9-48.0) months. We divided the patients into two groups (RTAD (retrograde type A dissection) group, N = 56; PNAD (proximal new aortic dissection) group, N = 57) according to their anatomical features. Survival analysis during the follow-up was evaluated using a Kaplan-Meier survival curve and a log-rank test. RESULTS: The 30-day mortality was 6.2% (7/113), the median follow-up period was 31.7 (IQR 14.7-65.6) months, and the overall survival at 1 year, 5 years, and 10 years was 88.5%, 88.5%, and 87.6%, respectively. Fourteen deaths occurred during the follow-up, but there were no late aorta-related deaths. Three patients underwent total thoracoabdominal aortic replacement 1 year after a second open operation. The RTAD group had a smaller ascending aorta size (42.5 ± 7.7 mm vs 48.4 ± 11.4 mm; P < .01) and a closer proximal landing zone (P < .01) compared to the PNAD group. However, there were no differences in survival between the two groups. CONCLUSIONS: TAAD can present as an early or a late complication after TEVAR due to stent-grafting-related issues or disease progression. Open operation can be performed to treat TAAD, and this has acceptable early and mid-term outcomes. Follow-up should become mandatory for patients after TEVAR because these patients are at increased risk for TAAD.

The Evaluation of Outcomes after Thoracic Endovascular Aortic Repair for Type B Aortic Dissection in Mainland China.

BACKGROUND: To assess the mortality and outcomes after thoracic endovascular aortic repair (TEVAR) in patients with type B aortic dissection (TBAD) in mainland China, and to compare these outcomes with data from Western countries, while analyzing the potential reasons for differences among different countries. METHODS: An extensive literature search spanning from January 1999 to October 2023 was conducted using PubMed, Cochrane Library, and Embase databases for studies on endovascular treatment for TBAD. This systematic review and meta-analysis adhered to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Data extraction and analysis followed the guidelines outlined in the Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement. Primary outcomes were in-hospital mortality and mid-term (< 5 years) mortality. RESULTS: Based on 25 publications (3,080 patients), pooled estimate for in-hospital mortality was 2.2% (95% confidence interval, 1.6%-2.9%). Major perioperative complications included stroke (2.4% [1.8%-3.3%]), spinal cord ischemia (1.4% [1.0%-2.2%]), retrograde type A aortic dissection (1.2% [0.8%-1.8%]), type I endoleak (5.6% [3.6%-8.6%]), visceral ischemia (1.0% [0.5%-2.1%]), and acute renal failure (2.8% [2.0%-3.8%]). Mid-term mortality was 5.1% (3.6%-7.3%), and secondary intervention rate was 4.9% (4.0%-6.0%) with 1.7% (1.0%-2.9%) conversion rate to open surgery. In subgroup analysis based on uncomplicated TBAD, in-hospital and mid-term mortality was 0.5% (0.2%-1.5%) and 0.6% (0.2-1.7%), respectively. Compared with data from Western countries, mainland Chinese patients had a lower mortality. CONCLUSIONS: In mainland China, the outcomes of endovascular treatment for TBAD are comparable to those of Western countries. The large number of patients undergoing TEVAR in mainland China and its good performance support the use of TEVAR in uncomplicated TBAD.

TRIM29 (Tripartite Motif Containing 29) Alleviates NLRC4 (NLR Family CARD Domain Containing Protein 4) Inflammasome Related Cerebral Injury via Promoting Proteasomal Degradation of NLRC4 in Ischemic Stroke.

BACKGROUND: Neuroinflammation plays extremely crucial roles in the neurological damage mediated by ischemic stroke. TRIM29 (tripartite motif containing 29) has previously been proposed to contribute to the regulation of innate immunity, however, the effect of TRIM29 on ischemic stroke induced neurodegenerative processes and neuroinflammation still largely unexplored. In the current article, we aimed to investigate the function and the precise mechanisms of TRIM29 in ischemic stroke. METHODS: Middle cerebral artery occlusion mice model and oxygen-glucose deprivation cell model were established as in vivo and in vitro models of ischemic stroke. Quantitative real-time polymerase chain reaction (PCR), Western blot, and ELSIA were used to detect the expression levels of TRIM29, cytokines, and marker proteins. Immunofluorescence assay was performed to examine the extent of cell death. Different truncations were generated, and coimmunoprecipitation assays were used to confirm the protein interaction. Ubiquitination assay was performed to detect the ubiquitination levels. RESULTS: We found that the cerebral ischemia-reperfusion induced injury was aggravated in TRIM29 knockout mice after middle cerebral artery occlusion operation as well as the increased neurological deficits score. TRIM29 expression was also found to be up-regulated upon middle cerebral artery occlusion or OGD administration, and loss of TRIM29 promoted the apoptosis and pyroptosis of neurons and microglial cells induced by middle cerebral artery occlusion or OGD, consistent with the enhanced proinflammatory mediators production and activation of NLRC4 (NLR [NOD-like receptor] family CARD [caspase recruitment domain] domain containing protein 4) inflammasome. Furthermore, we observed that TRIM29 interacted with NLRC4 directly and promoted the K48-linked polyubiquitination of NLRC4, lead to the proteasomal degradation of NLRC4. CONCLUSIONS: In conclusion, for the first time, we revealed the role of TRIM29 in ischemic stroke and illustrated the direct relationship between TRIM29 and NLRC4.

A CT-based predictive model for stent-induced vessel damage: application to type B aortic dissection.

OBJECTIVES: The distal stent-induced new entry (distal SINE) is a life-threatening device-related complication after thoracic endovascular aortic repair (TEVAR). However, risk factors for distal SINE are not fully determined, and prediction models are lacking. This study aimed to establish a predictive model for distal SINE based on the preoperative dataset. METHODS: Two hundred and six patients with Stanford type B aortic dissection (TBAD) that experienced TEVAR were involved in this study. Among them, thirty patients developed distal SINE. Pre-TEVAR morphological parameters were measured based on the CT-reconstructed configurations. Virtual post-TEVAR morphological and mechanical parameters were computed via the virtual stenting algorithm (VSA). Two predictive models (PM-1 and PM-2) were developed and presented as nomograms to help risk evaluation of distal SINE. The performance of the proposed predictive models was evaluated and internal validation was conducted. RESULTS: Machine-selected variables for PM-1 included key pre-TEVAR parameters, and those for PM-2 included key virtual post-TEVAR parameters. Both models showed good calibration in both development and validation subsamples, while PM-2 outperformed PM-1. The discrimination of PM-2 was better than PM-1 in the development subsample, with an optimism-corrected area under the curve (AUC) of 0.95 and 0.77, respectively. Application of PM-2 in the validation subsample presented good discrimination with an AUC of 0.9727. The decision curve demonstrated that PM-2 was clinically useful. CONCLUSION: This study proposed a predictive model for distal SINE incorporating the CT-based VSA. This predictive model could efficiently predict the risk of distal SINE and thus might contribute to personalized intervention planning. CLINICAL RELEVANCE STATEMENT: This study established a predictive model to evaluate the risk of distal SINE based on the pre-stenting CT dataset and planned device information. With an accurate VSA tool, the predictive model could help to improve the safety of the endovascular repair procedure. KEY POINTS: • Clinically useful prediction models for distal stent-induced new entry are still lacking, and the safety of the stent implantation is hard to guarantee. • Our proposed predictive tool based on a virtual stenting algorithm supports different stenting planning rehearsals and real-time risk evaluation, guiding clinicians to optimize the presurgical plan when necessary. • The established prediction model provides accurate risk evaluation for vessel damage, improving the safety of the intervention procedure.

Hemodynamic Study of Stanford Type B Aortic Dissection Based on Ex Vivo Porcine Aorta Models.

BACKGROUND: In this study, we aimed to evaluate hemodynamic influence of the dissected aortic system via various ex vivo type B aortic dissection (AD) models. METHODS: Twenty-four raw porcine aortas were harvested and randomly divided into 4 groups to create various aortic models. Model A was the control group, while models B to D indicated the AD group, where models B and C presented a proximal primary entry with the false lumen (FL) lengths of 15 and 20 cm, respectively, and model D presented a 20 cm FL with a proximal primary entry and a distal reentry. All the aortic models were connected to a mock circulation loop to attain the realistic flow and pressure status. The flow distribution rate (FDR) of the aortic branches was calculated. Doppler ultrasound was applied to visualize the AD structure and to attain the velocity of flow in both the true and false lumens. Several sections of the AD were stained with hematoxylin and eosin for histologic evaluation after the experiment. RESULTS: This study demonstrated that higher pressures were found for the AD group compared with the control group. The mean systolic pressures at the inlet of models A to D were 113.34±0.81, 120.58±0.52, 117.76±0.82, and 115.87±0.42 mm Hg, respectively. The FDRs of the celiac artery in models A to D were 8.65%, 8.32%±0.15%, 7.87%±0.13%, and 8.03%±0.21%, respectively. By ultrasound visualization, the velocity of the flow at the entry to the FL in the AD group ranged in 10 to 92 cm/s. The dissection flap presented pulsatile movement, especially in the models B and C which contained 1 primary entry without distal reentries. Histological examinations indicated that AD was located between the intimal and medial layers. CONCLUSIONS: Our ex vivo models demonstrated that the configuration of the dissected aorta influenced the pressure distribution. Moreover, the dissection flap affected the FDR of the aortic branches that possibly inducing malperfusion syndrome.

The Role of Location, Length, and Thickness of the Intimal Flap in the Propagation of Stanford Type B Aortic Dissection Based on Ex Vivo Porcine Aorta Models.

PURPOSE: To explore the role of location, length, and thickness of the intimal flap in the propagation of Stanford type B aortic dissection (TBAD) based on ex vivo porcine aorta models based on ex vivo porcine aorta models. MATERIALS AND METHODS: The porcine aortas were harvested and randomly divided into 6 groups to create various TBAD aortic models. We constructed intimal flaps for different locations (group A [entry tear on outer curvature] and group B [entry tear on inner curvature]), lengths (group C [long] and group D [short]), and thicknesses (group E [thick] and group F [thin]). For the ex vivo perfusion experiments conducted on model aortas, an experimental circulation loop (ECL) was employed. The pressure in false lumen (FL) was constantly monitored. A comparison was made between the morphological data collected before and after the experiment to quantify the changes in the FL after the experiment. RESULTS: Compared the results with group B, the mean peak pressures of the FL in group A were lower (106.87±15.55 vs. 124.01±22.75 mm Hg, p=0.028). The mean axial propagation length in group A was shown to be shorter than that of group B (88.14±33.38 vs. 197.43±41.65 mm, p<0.001). The mean peak pressure was higher in group C than in group D (144.04±19.37 vs. 92.51±26.70 mm Hg, p<0.001). The mean peak pressure of group E was higher than that of group F (160.83±32.83 vs. 109.33±15.62 mm Hg, p<0.001), as was the mean axial propagation length of group E (143.11±39.73 vs. 100.45±35.44 mm, p=0.021). According to the results of multivariable linear regression, axial propagation length=45.873-0.703×length of initial FL+0.863× peak pressure (p<0.001). CONCLUSION: There was a relationship between FL propagation and the location, length, and thickness of the intimal flap. The axial propagation length was related to the length of the intimal flap and the peak pressure of propagation. It may be helpful to evaluate the risk of propagation in patients with TBAD. CLINICAL IMPACT: This study found that the locations, lengths, and thickness of the intimal flap significantly contributed to propagation pressure of FL. Using dissection flap characteristics, a physician can predict FL development in a patient and formulate a treatment plan.The purpose was to investigate the relationship between the dissection flap characteristics (location, length, and thickness) and the propagation of the FL, which is not clear at present. This study employed porcine models to create an experimental circulation loop. The perfusion experiment was conducted using a FL without distal re-entry and a non-pulsating flow.

Qualitative and Quantitative Assessment of Invasive Surgery Skill Based on a Custom Training Simulator.

PURPOSE: Qualitative and quantitative assessment of interventional performance is a vital component in the evaluation of endovascular surgery skill training. We established a custom simulator with qualitative and quantitative metrics for endovascular performance training. METHODS: The simulator included an in vitro silicone phantom, mock circulation loop, visual module, force-sensing module, and custom software for image and force data postprocessing. Two tasks to deliver the guidewire to the target location of the carotid artery were conducted by the expert (n=4), novice (n=6), and test (n=4) groups. Seven features with significant differences extracted from the expert and novice groups were applied for qualitative assessment using the support vector machine (SVM) and quantitative assessment using the Mahalanobis distance (MD). RESULTS: Significant differences were observed in kinematic and force data between experts and novices during the intervention procedure. The median value of finished time for task 1 was 26.88 seconds for experts and 63.36 seconds for novices. The maximum speed for experts and novices was 32.79 and 7.43 cm/s, respectively. Moreover, the classified results depicted that the accuracy of qualitative assessment for task 1 and task 2 was 96.67% and 90%, respectively. As for the quantitative data, the residents had higher scores than individuals majored in biomedical engineering at 2 tasks (70.06±5.30 vs 41.81±6.58 for task 1, p=0.001). CONCLUSIONS: The proposed endovascular intervention skill training simulator provides qualitative and quantitative metrics on intervention performance skills and may be a useful tool in future interventional surgical training. CLINICAL IMPACT: This simulator comprised an in-vitro silicone phantom, mock circulation loop, visual module, force-sensing module, and custom software for image and force data post-processing. Seven interventional performance features were used for qualitative assessment using the support vector machine and quantitative assessment using the Mahalanobis Distance. From the observations, we conclude that this endovascular intervention skill training simulator provides qualitative and quantitative metrics on intervention performance and may be a useful tool in future surgical training.

Episodic memory in aspects of brain information transfer by resting-state network topology.

Cognitive functionality emerges due to neural interactions. The interregional signal interactions underlying episodic memory are a complex process. Thus, we need to quantify this process more accurately to understand how brain regions receive information from other regions. Studies suggest that resting-state functional connectivity (FC) conveys cognitive information; additionally, activity flow estimates the contribution of the source region to the activation pattern of the target region, thus decoding the cognitive information transfer. Therefore, we performed a combined analysis of task-evoked activation and resting-state FC voxel-wise by activity flow mapping to estimate the information transfer pattern of episodic memory. We found that the cinguloopercular (CON), frontoparietal (FPN) and default mode networks (DMNs) were the most recruited structures in information transfer. The patterns and functions of information transfer differed between encoding and retrieval. Furthermore, we found that information transfer was a better predictor of memory ability than previous methods. Additional analysis indicated that structural connectivity (SC) had a transportive role in information transfer. Finally, we present the information transfer mechanism of episodic memory from multiple neural perspectives. These findings suggest that information transfer is a better biological indicator that accurately describes signal communication in the brain and strongly influences the function of episodic memory.

Resting-State Functional MRI of Healthy Adults: Temporal Dynamic Brain Coactivation Patterns.

Background The aging brain is typically associated with aberrant interactions of large-scale intrinsic networks. However, the dynamic variation of these networks' coactivation or deactivation across the adult lifespan remains unclear. Purpose To promote the interpretation of dynamic brain network variations underlying the complex aging process by quantifying activation levels and obtaining a clear definition of coactivation patterns (CAPs) with resting-state functional MRI (rsfMRI). Materials and Methods In a retrospective study (October 2010 to September 2013), rsfMRI data from healthy participants in the Cambridge Centre for Ageing and Neuroscience (Cam-CAN) data repository were used to generate CAPs by applying single-volume temporal clustering analysis. Spatial clustering analysis was then performed to capture dynamic coactivation and deactivation within or between primary sensory networks and high-order cognitive networks (including the default mode network [DMN], attentional network [AN], and frontoparietal network [FPN]). Linear relationships between dynamic metrics and age were revealed with Spearman partial correlations. Results A total of 614 participants (mean age, 54 years ± 18 [SD]; 311 women) ranging in age from 18 to 88 years were evaluated. There was a negative correlation of the CAPs (Spearman correlations: r = -0.98, P < .001) with loss of coactivation (partial correlations: r = -0.17, P < .001) and deactivation (partial correlations: r = 0.216, P < .001) with aging. The CAPs, characterized by negative correlation patterns between the DMN and AN, occurred (partial correlations: r = 0.14, P = .003) and dwelled (partial correlations: r = 0.10, P = .04) more with aging. Moreover, the AN and DMN CAP transitioned more to the AN and FPN CAP with aging (partial correlations: r = 0.17, P < .001). Conclusion The dynamics of the healthy aging brain are characterized mainly by more flexibility of the high-order cognitive networks while maintaining primary sensory functions (networks). Online supplemental material is available for this article. © RSNA, 2022 See also the editorial by Holodny in this issue.

A Mock Circulation Loop for In Vitro Hemodynamic Evaluation of Aorta: Application in Aortic Dissection.

PURPOSE: Aortic dissection (AD) is a catastrophic disease with complex hemodynamic conditions, however, understandings regarding its perfusion characteristics were not sufficient. In this study, a mock circulation loop (MCL) that integrated the Windkessel element and patient-specific silicone aortic phantoms was proposed to reproduce the aortic flow environment in vitro. MATERIALS AND METHODS: Patient-specific normal and dissected aortic phantoms with 12 branching vessels were established and embedded into this MCL. Velocities for aortic branches based on 20 healthy volunteers were regarded as the standardized data for flow division. By altering boundary conditions, the proposed MCL could mimic normal resting and left-sided heart failure (LHF) conditions. Flow rates and pressure status of the aortic branches could be quantified by separate sensors. RESULTS: In normal resting condition, the simulated heart rate and systemic flow rate were 60 bpm and 4.85 L/minute, respectively. For the LHF condition, the systolic and diastolic blood pressures were 75.94±0.77 mmHg and 57.65±0.35 mmHg, respectively. By tuning the vascular compliance and peripheral resistance, the flow distribution ratio (FDR) of each aortic branch was validated by the standardized data in the normal aortic phantom (mean difference 2.4%±1.70%). By comparing between the normal and dissected aortic models under resting condition, our results indicated that the AD model presented higher systolic (117.82±0.60 vs 108.75±2.26 mmHg) and diastolic (72.38±0.58 vs 70.46±2.33 mmHg) pressures, the time-average velocity in the true lumen (TL; 36.95 cm/s) was higher than that in the false lumen (FL; 22.95 cm/s), and the blood transport direction between the TL and FL varied in different re-entries. CONCLUSIONS: The proposed MCL could be applied as a research tool for in vitro hemodynamic analysis of the aorta diseases under various physical conditions.

Redclaw crayfish (Cherax quadricarinatus) responds to Vibrio parahaemolyticus infection by activating toll and immune deficiency signaling pathways and transcription of associated immune response genes.

In invertebrates, several genes controlled by the Toll and immunodeficiency (IMD) signaling cascade are altered during microbial infection. However, little is known about the expression patterns of innate immune response genes in red-clawed crayfish (Cherax quadricarinatus). In the present study, the transcription of five genes was assessed in C. quadricarinatus challenged with Vibrio parahaemolyticus (V. parahaemolyticus). The expression of Relish, Toll-like receptor (TLR), tumor necrosis factor receptor-related factor 6 (TRAF6), Akirin, and IMD in different tissues and at different time points after infection were assessed. In addition, the Relish gene was amplified, the protein conformation of the Relish gene was predicted, and gene expression changes associated with antimicrobial peptide production in C. quadricarinatus were analyzed using RNA interference (RNAi). During V. parahaemolyticus infection, the transcripts of the above five genes were significantly increased in the hepatopancreas of C. quadricarinatus (P < 0.05). In contrast, TLR was significantly downregulated in muscle tissue at the initial stage of infection (P < 0.05); TRAF6 and IMD were significantly down-regulated throughout infection (P < 0.05); Akirin transcripts had the lowest abundance at 24 h post-infection; Relish, IMD and Akirin genes were significantly up-regulated in gill tissue at the early stage of infection (P < 0.05); only TRAF6 was significantly up-regulated at 6, 24 and 48 h after infection. The Relish gene of C. quadricarinatus is closely related to the Exopalaemon carinicauda. When the Relish gene was knocked down by RNAi, the V. parahaemolyticus challenge showed that the mortality rate of the RANi group was significantly higher than that of the NC group; pathological sections showed that the hepatopancreatic tissue damage was the most severe 12 h after the interference; and the interference significantly inhibited IRF4, NF-κB, ALF, laccase, SOD1, and lectin genes. Therefore, it can be hypothesized that the Toll and IMD pathways are activated in C. quadricarinatus in response to bacterial infection and that genes associated with these pathways are differentially transcribed in different tissues. This study provides insights into the Toll and IMD signaling pathways and the spatiotemporal expression of key genes regulating bacterial infection resistance in C. quadricarinatus.

A new potential risk: The impacts of Klebsiella pneumoniae infection on the histopathology, transcriptome and metagenome of Chinese mitten crab (Eriocheir sinensis).

Klebsiella pneumoniae is a common conditional pathogen found in natural soil water sources and vegetation and can infect invertebrates, vertebrates, and plants. In this study, we isolated K. pneumoniae from the hepatopancreas of the Chinese mitten crab (Eriocheir sinensis) for the first time and then we analysed its effects of on the histopathological changes, the transcriptome of the hepatopancreas, and the gut microbiota of this crab species. The findings of this study showed that K. pneumoniae infection has led to significant structural changes in the hepatopancreas, such as the production of vacuolated tissue structures, disorganized cell arrangement, and lysis of some hepatopancreatic cells. Also, the infection caused activation of the antioxidant-related enzymes such as SOD and CAT by inducing oxidative stress. The transcriptome of the hepatopancreas identified 10,940 differentially expressed genes (DEGs) in the susceptible (SG) groups and control (CG) groups, and 8495 DEGs in the SG groups and anti-infective (AI) groups. The KEGG pathway revealed upregulated DEGs caused by K. pneumoniae infection that involved in the immune response and apoptotic functional pathways, and also downregulated DEGs involved in the digestive absorption, metabolic, and biosynthetic signaling pathways. Meanwhile, metagenics sequencing revealed that at the phylum, class, order, family, and genus levels, K. pneumoniae infection altered the composition of the gut microbiota of E. sinensis, through increasing the abundance of Prolixibacteraceae, Enterobacterales, and Roseimarinus and decreasing the abundance of Alphaproteobacteria. The flora structure has also been changed between the SG and AI groups, with the abundance of Firmicutes, Erysipelotrichales, and Erysipelotrichaceae that were significantly decreased in the SG groups than in the AI groups. But, the abundance of Acinetobacter was considerably higher than in the AI group. In summary, K. pneumoniae infection induced oxidative stress in E. sinensis, triggered changes in immune-related gene expression, and caused structural changes in the gut microbiota. This study provides data to support the analysis of bacterial infection probes in several crustacean species.

Population Receptive Field Characteristics in the between- and Within-Digit Dimensions of the Undominant Hand in the Primary Somatosensory Cortex.

Somatotopy is an important guiding principle for sensory fiber organization in the primary somatosensory cortex (S1), which reflects tactile information processing and is associated with disease-related reorganization. However, it is difficult to measure the neuronal encoding scheme in S1 in vivo in normal participants. Here, we investigated the somatotopic map of the undominant hand using a Bayesian population receptive field (pRF) model. The model was established in hand space with between- and within-digit dimensions. In the between-digit dimension, orderly representation was found, which had low variability across participants. The pRF shape tended to be elliptical for digits with high spatial acuity, for which the long axis was along the within-digit dimension. In addition, the pRF width showed different change trends in the 2 dimensions across digits. These results provide new insights into the neural mechanisms in S1, allowing for in-depth investigation of somatosensory information processing and disease-related reorganization.

Hemodynamic response varies across tactile stimuli with different temporal structures.

Tactile stimuli can be distinguished based on their temporal features (e.g., duration, local frequency, and number of pulses), which are fundamental for vibrotactile frequency perception. Characterizing how the hemodynamic response changes in shape across experimental conditions is important for designing and interpreting fMRI studies on tactile information processing. In this study, we focused on periodic tactile stimuli with different temporal structures and explored the hemodynamic response function (HRF) induced by these stimuli. We found that HRFs were stimulus-dependent in tactile-related brain areas. Continuous stimuli induced a greater area of activation and a stronger and narrower hemodynamic response than intermittent stimuli with the same duration. The magnitude of the HRF increased with increasing stimulus duration. By normalizing the characteristics into topographic matrix, nonlinearity was obvious. These results suggested that stimulation patterns and duration within a cycle may be key characters for distinguishing different stimuli. We conclude that different temporal structures of tactile stimuli induced different HRFs, which are essential for vibrotactile perception and should be considered in fMRI experimental designs and analyses.

Influence of layered skull modeling on the frequency sensitivity and target accuracy in simulations of transcranial current stimulation.

With the development of electrical stimulation technology, especially the emergence of temporally interfering (TI) stimulation, it is necessary to discuss the influence of current frequency on stimulation intensity. Accurate skull modeling is important for transcranial current stimulation (tCS) simulation prediction because of its large role in dispersing current. In this study, we simulated different frequencies of transcranial alternating current stimulation (tACS) and TI stimulation in single-layer and layered skull model, compared the electric field via error parameters such as the relative difference measure and relative magnification factor. Pearson correlation analysis and t-test were used to measure the differences in envelope amplitude. The results showed that the intensity of electric field in the brain generated by per unit of stimulation current will increase with current frequency, and the layered skull model had a better response to frequency. An obvious pattern difference was found between the electric fields of the layered and single-layer skull individualized models. For TI stimulation, the Pearson correlation coefficient between the envelope distribution of the layered skull model and the single-layer skull was only 0.746 in the individualized model, which is clearly lower than the correlation coefficient of 0.999 determined from the spherical model. Higher carrier frequencies seemed to be easier to generate a large enough brain electric field envelope in TI stimulation. In conclusion, we recommend using layered skull models instead of single-layer skull models in tCS (particularly TI stimulation) simulation studies in order to improve the accuracy of the prediction of stimulus intensity and stimulus target.

3D Morphologic Findings Before and After Thoracic Endovascular Aortic Repair for Type B Aortic Dissection.

BACKGROUND: Stanford type-B aortic dissection (TBAD) is commonly treated by thoracic endovascular aortic repair (TEVAR). Usually, the implanted stent-grafts will not cover the entire dissection-affected region for those patients with dissection extending beyond the thoracic aorta, thus the fate of the uncovered aortic segment is uncertain. This study used 3-dimensional measurement of aortic morphological changes to classify the different remodeling effects of TBAD patients after TEVAR, and hypothesized that not only initial morphological features, but also their change over time at follow-up are associated with the remodeling. METHODS: Forty-one TBAD patients underwent TEVAR and CT-angiography before and after the intervention (twice or more follow-ups) were included in this study. According to the false-lumen volume variations post-TEVAR, patients who had abdominal aortic expansion at the second follow-up were classified into the Enlarged (n =12, 29%) and remaining into the Stable group (n = 29, 71%). 3D morphological parameters were extracted on precise reconstruction of imaging datasets. Statistical differences in 3D morphological parameters over time between the 2 groups and the relationship among these parameters were analyzed. RESULTS: In the Enlarged group, the number of all tears before TEVAR was significantly higher (P = 0.022), and the size of all tears at the first and second follow-up post-TEVAR were significantly higher than that in the Stable group (P = 0.008 and P = 0.007). The location of the primary tear was significantly higher (P = 0.031) in the Stable group. The cross-sectional analysis of several slices below the primary tear before TEVAR shows different shape features of the false lumen in the Stable (cone-like) and Enlarged (hourglass-like) groups. The number of tears before TEVAR has a positive correlation with the post-TEVAR development of dissection (r = 0.683, P = 0.00). CONCLUSION: The results in this study indicated that the TBAD patients with larger tear areas, more re-entry tears and with the primary tear proximal to the arch would face a higher risk of negative remodeling after TEVAR.

Hepatopancreatic transcriptome analysis and humoral immune factor assays in red claw crayfish (Cherax quadricarinatus) provide insight into innate immunomodulation under Vibrio parahaemolyticus infection.

Red claw crayfish (Cherax quadricarinatus) is an economically and nutritionally important specie. We aimed to assess the immunostimulatory response to C. quadricarinatus infection with Vibrio parahaemolyticus. After determining the LD50, we infected C. quadricarinatus and examined the differential expression profiles of hepatopancreas transcriptional genes, and observed the temporal changes of hepatopancreas pathological sections and serum immunoenzymatic activities at different time points to reveal the infection mechanism of V. parahaemolyticus and the immune detoxification mechanism of the organism. The results showed that V. parahaemolyticus infection with C. quadricarinatus caused hepatopancreas injury and the immune enzyme activity of the organism changed with time delay. Transcriptome analysis of 47,338 single genes obtained by RNA sequencing and de nove transcriptome assembly identified a total of 3678 differentially expressed genes (P < 0.05) in the expression profiles of susceptible and normal animals for comparative analysis, and 2516 differentially expressed genes (P < 0.05) in the expression profiles of asymptomatic (infection-resistant) and normal animals. GO and KEGG and analyses revealed immune-related pathways under V. parahaemolyticus infection, including Vibrio cholerae infection, phagosome, lysozyme, oxidative phosphorylation, antigen processing and presentation, apoptosis, and Toll-like receptor signaling, as well as significant differences in the expression patterns of related immune genes at different times (P < 0.05). These new experimental results reveal the molecular response of the hepatopancreas to V. parahaemolyticus infection and the corresponding adaptive mechanisms, thus further revealing the pathogenesis due to bacterial infection in the aquatic environment, and providing a reference for further understanding of microbial-host interactions in aquatic systems.

A new insight to characterize immunomodulation based on hepatopancreatic transcriptome and humoral immune factor analysis of the Cherax quadricarinatus infected with Aeromonas veronii.

Cherax quadricarinatus is a type of large freshwater crayfish that is characterized by rapid growth and formidable adaptability. It has also been widely cultured and studied as a model organism. Aeromonas veronii is the dominant pathogen in aquatic environments and the primary threat to aquaculture's economic stability. To better understand the interactions between C. quadricarinatus and A. veronii, high-throughput RNA sequencing of the C. quadricarinatus hepatopancreas was carried out on a control group, susceptible group (6 h after infection), and resistant group (48 h after infection). A total of 65,850,929 genes were obtained. Compared with the control group, 2616 genes were up-regulated and 1551 genes were down-regulated in the susceptible group; while 1488 genes were up-regulated and 1712 genes were down-regulated in the resistant group. GO and KEGG analysis showed that these differentially expressed genes (DEGs) were associated with multiple immune pathways, including Toll-like receptors (TLRs), antigen processing and presentation, NOD-like receptor signaling pathway, phagosome, lysosome, JAK-STAT signaling pathway. qRT-PCR showed that infection by A. veronii changed the expression pattern of the serine proteinase inhibitor (SPI), crustacean hyperglycemic hormone (CHH), anti-lipopolysaccharide factor (ALF), and extracellular copper/zinc superoxide dismutase (SOD1), all of which were significantly higher than in the control group up to 48 h after infection. In addition, detection of superoxide dismutase (SOD), catalase (CAT), lysozyme (LZM), and phenoloxidase (PO) activity, as well as ceruloplasmin (CP) concentration at different times after infection showed diverse trends. Furthermore, pathological sections obtained 24 h after infection show lesions on the hepatopancreas and intestinal tissues caused by A. veronii. The results of this study provide a foundation for analyzing the immune mechanism of C. quadricarinatus infected with A. veronii at the transcriptional level and a theoretical basis for screening disease-resistant individuals to ensure healthy economic development of the aquatic industry.

Transcriptome analysis of the Macrobrachium nipponense hepatopancreas provides insights into immunoregulation under Aeromonas veronii infection.

The oriental river prawn Macrobrachium nipponense is a commercially important freshwater shrimp that is widely farmed in China. Aeromonas veronii is a conditional pathogen of farmed shrimp, which has caused huge economic losses to the industry. Therefore, there is urgency to study the host-pathogen interactions between M. nipponense and A. veronii to screen individuals with antimicrobial resistance. In this study, we examined the hepatopancreas of moribund M. nipponense infected with A. veronii and healthy individuals at both the histopathological and transcriptomic levels. We showed that A. veronii infection resulted in tubular necrosis of the M. nipponense hepatopancreas. Such changes likely affect assimilation, storage, and excretion by the hepatopancreas, which could ultimately affect the survival and growth of infected individuals. Among the 61,345 unigenes obtained through RNA sequencing and de novo transcriptome assembly, 232 were differentially expressed between the two groups. KEGG and GO analyses revealed that these differentially expressed genes were implicated in pathways, including PPAR, PI3K/AKT, and AMPK signaling. The results of this study will contribute to an analysis of the immune response of M. nipponense to A. veronii infection at the transcriptomic level. Furthermore, the RNA-seq data generated here provide an important genomic resource for research on M. nipponense in the absence of a reference genome.