Image-Guided Autonomous Guidewire Navigation in Robot-Assisted Endovascular Interventions using Reinforcement Learning

Autonomous robots in endovascular interventions possess the potential to navigate guidewires with safety and reliability, while reducing human error and shortening surgical time. However, current methods of guidewire navigation based on Reinforcement Learning (RL) depend on manual demonstration data or magnetic guidance. In this work, we propose an Image-guided Autonomous Guidewire Navigation (IAGN) method. Specifically, we introduce BDA-star, a path planning algorithm with boundary distance constraints, for the trajectory planning of guidewire navigation. We established an IAGN-RL environment where the observations are real-time guidewire feeding images highlighting the position of the guidewire tip and the planned path. We proposed a reward function based on the distances from both the guidewire tip to the planned path and the target to evaluate the agent's actions. Furthermore, in policy network, we employ a pre-trained convolutional neural network to extract features, mitigating stability issues and slow convergence rates associated with direct learning from raw pixels. Experiments conducted on the aortic simulation IAGN platform demonstrated that the proposed method, targeting the left subclavian artery and the brachiocephalic artery, achieved a 100% guidewire navigation success rate, along with reduced movement and retraction distances and trajectories tend to the center of the vessels

UDCR: Unsupervised Aortic DSA/CTA Rigid Registration Using Deep Reinforcement Learning and Overlap Degree Calculation

The rigid registration of aortic Digital Subtraction Angiography (DSA) and Computed Tomography Angiography (CTA) can provide 3D anatomical details of the vasculature for the interventional surgical treatment of conditions such as aortic dissection and aortic aneurysms, holding significant value for clinical research. However, the current methods for 2D/3D image registration are dependent on manual annotations or synthetic data, as well as the extraction of landmarks, which is not suitable for cross-modal registration of aortic DSA/CTA. In this paper, we propose an unsupervised method, UDCR, for aortic DSA/CTA rigid registration based on deep reinforcement learning. Leveraging the imaging principles and characteristics of DSA and CTA, we have constructed a cross-dimensional registration environment based on spatial transformations. Specifically, we propose an overlap degree calculation reward function that measures the intensity difference between the foreground and background, aimed at assessing the accuracy of registration between segmentation maps and DSA images. This method is highly flexible, allowing for the loading of pre-trained models to perform registration directly or to seek the optimal spatial transformation parameters through online learning. We manually annotated 61 pairs of aortic DSA/CTA for algorithm evaluation. The results indicate that the proposed UDCR achieved a Mean Absolute Error (MAE) of 2.85 mm in translation and 4.35{\deg} in rotation, showing significant potential for clinical applications

Leucine Carboxyl Methyltransferase Downregulation and Protein Phosphatase Methylesterase Upregulation Contribute Toward the Inhibition of Protein Phosphatase 2A by α-Synuclein

The pathology of Parkinson’s disease (PD) is characterized by intracellular neurofibrillary tangles of phosphorylated α-synuclein (α-syn). Protein phosphatase 2A (PP2A) is responsible for α-syn dephosphorylation. Previous work has demonstrated that α-syn can regulate PP2A activity. However, the mechanisms underlying α-syn regulation of PP2A activity are not well understood. In this study, we found that α-syn overexpression induced increased α-syn phosphorylation at serine 129 (Ser129), and PP2A inhibition, in vitro and in vivo. α-syn overexpression resulted in PP2A demethylation. This demethylation was mediated via downregulated leucine carboxyl methyltransferase (LCMT-1) expression, and upregulated protein phosphatase methylesterase (PME-1) expression. Furthermore, LCMT-1 overexpression, or PME-1 inhibition, reversed α-syn-induced increases in α-syn phosphorylation and apoptosis. In addition to post-translational modifications of the catalytic subunit, regulatory subunits are involved in the regulation of PP2A activity. We found that the levels of regulatory subunits which belong to the PPP2R2 subfamily, not the PPP2R5 subfamily, were downregulated in the examined brain regions of transgenic mice. Our work identifies a novel mechanism to explain how α-syn regulates PP2A activity, and provides the optimization of PP2A methylation as a new target for PD treatment

Clinical application analysis of Da Vinci Xi robot in thyroid surgery using a gasless, unilateral axillary approach

Background and purpose: Robotic thyroid surgery has been carried out worldwide since Kang first applied it to the thyroid in 2007. The proportion of axillary approach is increasing rapidly in China due to the continuous verification of safety, radicalness and cosmetic properties of cancer treatment. The advantages and clinical value of Da Vinci Xi robotic unilateral axillary approach in the treatment of unilateral papillary thyroid microcarcinoma (PTMC) was investigated by comparing and analyzing the clinical efficacy in 95 patients undergoing a gasless, unilateral axillary approach Da Vinci Xi robotic thyroid surgery for PTMC and 91 patients undergoing conventional surgery. Methods: The clinical data of 186 cases of unilateral PTMC undergoing thyroidectomy in the Department of Head and Neck Surgery of Shanghai cancer Hospital from March 2020 to November 2021 were retrospectively analyzed, and they were divided into the robotic group (95 cases) and the open group (91 cases) according to the surgical methods. The general clinical data, surgical results, postoperative complications, satisfaction of incision, learning curve and surgical costs were analyzed and compared between the two groups. Results: There was no statistically significant difference between the two groups in gender, age, incidence of Hashimoto’s thyroiditis, tumor diameter, location and number of lesions (P>0.05). However, the operation time was significantly longer in the robotic group [(126.65±34.76) min]than in the open group [(60.99±21.12) min], and after 36 operations, the operation time reached a stable level. The operation cost was significantly higher in the robotic group [(47 940.66±4 404.30) yuan] than in the open group [(15 807.73±2 295.35) yuan]. There was no significant difference in intraoperative hemorrhage [robotic group: (20.48±18.83) mL; open group: (16.15±13.95) mL], the number of removed lymph nodes (robotic group: 2.61±2.77; open group: 2.97±2.20) and the number of positive lymph nodes (robotic group: 1.01±1.61; open group: 0.78±1.36) between the two groups (P>0.05). The incidence of postoperative temporary vocal hoarseness and transient hypocalcemia was lower in the robotic group (1.10%, 2.10%, respectively) than in the open group (2.20%, 3.30%, respectively), however there was no statistically significant difference (P>0.05). The postoperative satisfaction of incision was significantly higher in the robotic group (very satisfied 87.4%, satisfied 11.6%) than in the open group (very satisfied 71.4%, satisfied 26.4%), and the difference was statistically significant (P<0.05). Conclusion: Da Vinci Xi robot in thyroid surgery using a gasless, unilateral axillary approach has not only good cosmetic effect and high patient satisfaction, but also short learning curve. The amount of bleeding during the surgery, the lymph node detection and the occurrence of postoperative complications are comparable to the traditional surgery

Good learning environment of medical schools is an independent predictor for medical students’ study engagement

BackgroundStudy engagement is regarded important to medical students’ physical and mental wellbeing. However, the relationship between learning environment of medical schools and the study engagement of medical students was still unclear. This study was aimed to ascertain the positive effect of learning environment in study engagement.MethodsWe collected 10,901 valid questionnaires from 12 medical universities in China, and UWES-S was utilized to assess the study engagement levels. Then Pearson Chi-Square test and Welch’s ANOVA test were conducted to find the relationship between study engagement and learning environment, and subgroup analysis was used to eradicate possible influence of confounding factors. After that, a multivariate analysis was performed to prove learning environment was an independent factor, and we constructed a nomogram as a predictive model.ResultsWith Pearson Chi-Square test (p < 0.001) and Welch’s ANOVA test (p < 0.001), it proved that a good learning environment contributed to a higher mean of UWES scores. Subgroup analysis also showed statistical significance (p < 0.001). In the multivariate analysis, we could find that, taking “Good” as reference, “Excellent” (OR = 0.329, 95%CI = 0.295–0.366, p < 0.001) learning environment was conducive to one’s study engagement, while “Common” (OR = 2.206, 95%CI = 1.989–2.446, p < 0.001), “Bad” (OR = 2.349, 95%CI = 1.597–3.454, p < 0.001), and “Terrible” (OR = 1.696, 95%CI = 1.015–2.834, p = 0.044) learning environment only resulted into relatively bad study engagement. Depending on the result, a nomogram was drawn, which had predictive discrimination and accuracy (AUC = 0.680).ConclusionWe concluded that learning environment of school was an independent factor of medical student’s study engagement. A higher level of learning environment of medical school came with a higher level of medical students’ study engagement. The nomogram could serve as a predictive reference for the educators and researchers

The Tumor Vessel Targeting Strategy: A Double-Edged Sword in Tumor Metastasis

Tumor vessels provide essential paths for tumor cells to escape from the primary tumor and form metastatic foci in distant organs. The vessel targeting strategy has been widely used as an important clinical cancer chemotherapeutic strategy for patients with metastatic tumors. Our review introduces the contribution of angiogenesis to tumor metastasis and summarizes the application of Food and Drug Administration (FDA)-approved vessel targeting drugs for metastatic tumors. We recommend the application and mechanisms of vascular targeting drugs for inhibiting tumor metastasis and discuss the risk and corresponding countermeasures after vessel targeting treatment

RcPAL, a key gene in lignin biosynthesis in Ricinus communis L.

Abstract Background Castor (Ricinus communis L.) is an important seed oil crop. Castor oil is a highly demanded oil for several industrial uses. Current castor bean varieties suffer from low productivity and high risk of insect pests and diseases. High productive and pest/disease resistance varieties are needed. Lignin has been associated to the resistance for pest, disease and lodging. Lignin is produced from several metabolites of the phenylpropanoid pathway. PAL is the key enzyme of the phenylpropanoid pathway. The gene PAL may assist in the improvement of resistance of castor bean. Results The RcPAL CDs was amplified and its function was examined by transgenic overexpression and antisense expression, lignin histochemical staining, real-time PCR, lignin content measurement and morphological investigation. Its full length was 2145 bp, encoding 714 amino acids. The overexpression of RcPAL (7.2 times) increased significantly the PAL activity, dyeing depth of xylem cells and lignin content (14.44%), resulting in a significantly lower plant height, deeper and thicker blade, more green leaves, shorter internode, thicker stem diameter, and opposite in antisense expression plants (lignin content lowered by 27.1%), demonstrated that the gene RcPAL was a key gene in castor lignin biosynthesis. Conclusions The gene RcPAL is a key gene in castor lignin biosynthesis and can be induced to express under mechanical damage stress. When up-regulated, it increased the lignin content significantly and dwarfed the plant height, and opposite when down-regulated. The gene RcPAL may assist in the improvement of resistance and plant type of castor bean

Three-Dimensional Copper Foil-Powder Sintering Current Collector for a Silicon-Based Anode Lithium-Ion Battery

In this work, we propose a facile method for manufacturing a three-dimensional copper foil-powder sintering current collector (CFSCC) for a silicon-based anode lithium-ion battery. We found that the CFSCC is suitable as a silicon-based paste electrode, and the paste-like electrodes are commonly used in industrial production. Compared with flat current collectors, the CFSCC better constrained the silicon volume change during the charging-discharging process. The capacitance of electrodes with CFSCC remained as high as 92.2% of its second cycle after 40 cycles, whereas that of electrodes with a flat current collector only remained at 50%