A Comprehensive Introduction of Visual-Inertial Navigation

In this article, a tutorial introduction to visual-inertial navigation(VIN) is presented. Visual and inertial perception are two complementary sensing modalities. Cameras and inertial measurement units (IMU) are the corresponding sensors for these two modalities. The low cost and light weight of camera-IMU sensor combinations make them ubiquitous in robotic navigation. Visual-inertial Navigation is a state estimation problem, that estimates the ego-motion and local environment of the sensor platform. This paper presents visual-inertial navigation in the classical state estimation framework, first illustrating the estimation problem in terms of state variables and system models, including related quantities representations (Parameterizations), IMU dynamic and camera measurement models, and corresponding general probabilistic graphical models (Factor Graph). Secondly, we investigate the existing model-based estimation methodologies, these involve filter-based and optimization-based frameworks and related on-manifold operations. We also discuss the calibration of some relevant parameters, also initialization of state of interest in optimization-based frameworks. Then the evaluation and improvement of VIN in terms of accuracy, efficiency, and robustness are discussed. Finally, we briefly mention the recent development of learning-based methods that may become alternatives to traditional model-based methods.Comment: 35 pages, 10 figure

Interfacial Properties of Bilayer and Trilayer Graphene on Metal Substrates

One popular approach to prepare graphene is to grow them on transition metal substrates via chemical vapor deposition. By using the density functional theory with dispersion correction, we systematically investigate for the first time the interfacial properties of bilayer (BLG) and trilayer graphene (TLG) on metal substrates. Three categories of interfacial structures are revealed. The adsorption of B(T)LG on Al, Ag, Cu, Au, and Pt substrates is a weak physisorption, but a band gap can be opened. The adsorption of B(T)LG on Ti, Ni, and Co substrates is a strong chemisorption, and a stacking-insensitive band gap is opened for the two uncontacted layers of TLG. The adsorption of B(T)LG on Pd substrate is a weaker chemisorption, with a band gap opened for the uncontacted layers. This fundamental study also helps for B(T)LG device study due to inevitable graphene/metal contact.Comment: 1 table, 8 figure

Exploring Speech Enhancement for Low-resource Speech Synthesis

High-quality and intelligible speech is essential to text-to-speech (TTS) model training, however, obtaining high-quality data for low-resource languages is challenging and expensive. Applying speech enhancement on Automatic Speech Recognition (ASR) corpus mitigates the issue by augmenting the training data, while how the nonlinear speech distortion brought by speech enhancement models affects TTS training still needs to be investigated. In this paper, we train a TF-GridNet speech enhancement model and apply it to low-resource datasets that were collected for the ASR task, then train a discrete unit based TTS model on the enhanced speech. We use Arabic datasets as an example and show that the proposed pipeline significantly improves the low-resource TTS system compared with other baseline methods in terms of ASR WER metric. We also run empirical analysis on the correlation between speech enhancement and TTS performances.Comment: Submitted to ICASSP 202

Clinical efficacy and safety of robotic retroperitoneal lymph node dissection for testicular cancer: a systematic review and meta-analysis

BackgroundRetroperitoneal lymph node dissection (RPLND) is an effective treatment for testicular tumors. In recent years, with the development of robotics, many urological procedures performed via standard laparoscopy have been replaced by robots. Our objective was to compare the safety and efficacy of robotic retroperitoneal lymph node dissection (R-RPLND) versus Non-robotic retroperitoneal lymph node dissection (NR-RPLND) in testicular cancer.MethodsPubmed, Embase, Scopus, Cochrane Library, and Web of Science databases were searched for literature on robotic surgery for testicular germ cell tumors up to April 2023. The statistical and sensitivity analyses were performed using Review Manager 5.3. Meta-analysis was performed to calculate mean difference (MD), odds ratio(OR), and 95% confidence interval (CI) effect indicators.ResultsEight studies with 3875 patients were finally included in this study, 453 with R-RPLND and 3422 with open retroperitoneal lymph node dissection (O-RPLND)/laparoscopic retroperitoneal lymph node dissection (L-RPLND). The results showed that R-RPLND had lower rates of intraoperative blood loss (MD = -436.39; 95% CI -707.60 to -165.19; P = 0.002), transfusion (OR = 0.06; 95% CI 0.01 to 0.26; P = 0.0001), total postoperative complication rates (OR = 0.39; 95% CI 0.21 to 0.70; P = 0.002), and length of stay (MD=-3.74; 95% CI -4.69 to -2.78; P<0.00001). In addition, there were no statistical differences between the two groups regarding perioperative and oncological outcomes regarding total operative time, the incidence of postoperative complications grade≥III, abnormal ejaculation rate, lymph node yield, and postoperative recurrence rate.ConclusionsThe R-RPLND and O-RPLND/L-RPLND provide safe and effective retroperitoneal lymph node dissection for testicular cancer. Patients with R-RPLND have less intraoperative bleeding, shorter hospitalization period, fewer postoperative complications, and faster recovery. It should be considered a viable alternative to O-RPLND/L-RPLND.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO, identifier CRD42023411696

Graphdiyne-metal contacts and graphdiyne transistors

Graphdiyne is prepared on metal surface, and making devices out of it also inevitably involves contact with metals. Using density functional theory with dispersion correction, we systematically studied for the first time the interfacial properties of graphdiyne contacting with a series of metals (Al, Ag, Cu, Au, Ir, Pt, Ni, and Pd). Graphdiyne is in an n-type Ohmic or quasi-Ohmic contact with Al, Ag, and Cu, while it is in a Schottky contact with Au (at source/drain interface), Pd, Pt, Ni, and Ir (at source/drain-channel interface), with high Schottky barrier heights of 0.39, 0.21 (n-type), 0.30, 0.41, and 0.45 (p-type) eV, respectively. A graphdiyne field effect transistor (FET) with Al electrodes is simulated by using quantum transport calculations. This device exhibits an on-off ratio up to 104 and a very large on-state current of 1.3 * 104 mA/mm in a 10 nm channel length. Thus, a new prospect is opened up for graphdiyne in high performance nanoscale devices.Comment: 27 pages, 9 figure

The feasibility of using remote magnetic navigation system as the primary technological training tool for novice cardiac electrophysiology operators in the catheter ablation of left-sided accessory pathway

Background: For novice operators, mastering catheter ablation of left-sided accessory pathway (LSAP) in a short duration of time without compromising efficacy and safety remains a challenge. In this study an attempt to shorten the learning curve by using robotics via a remote magnetic navigation (RMN) system was performed. Methods: Novice physician fellows without prior catheter ablation experience initiated their process of learning LSAP ablation using the Niobe™ RMN system. Their procedure parameters were recorded and compared with experienced operators using RMN and manual catheter navigation (MCN). Results: Novice operators quickly shortened the total procedure time after their first five procedures. In subsequent procedures, no significant difference in procedure time, fluoroscopy exposure or ablation time was observed between novice and experienced RMN operators. When compared to MCN operators, novice operators avoided excessive radiation exposure beginning with their first RMN procedure, while lower fluoroscopy doses were noted after five procedures. It was observed that procedure parameters did not differ significantly according to LSAP location. Conclusion: The RMN system is a practical and easy to use tool for novice electrophysiology operators to quickly master LSAP ablation, without compromising efficacy or safety. Additionally, when compared to MCN it also protects the operators and patients from excessive radiation exposure during the procedure

31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two

Background The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd. Methods We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background. Results First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001). Conclusions In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival