Experimental and simulation study on nonlinear pitch control of Seagull underwater glider

1008-1015The Seagull underwater glider, developed by the Shanghai Jiao Tong University, is designed as a test-bed glider for the development and validation of various algorithms to enhance the glider’s long-term autonomy. In this paper, an adaptive backstepping control (ABC) method is proposed for the nonlinear pitch control of the underwater glider gliding in the vertical plane. The linear quadratic regulator (LQR) control and proportional-integral-derivative (PID) control are applied and evaluated with the ABC method to control a glider in saw-tooth motion. Simulation results demonstrate inherent effectiveness and superiority of the LQR or PID based method. According to Lyapunov stability theory, the ABC control scheme is derived to ensure the tracking errors asymptotically converge to zero. The ABC controller has been implemented on Seagull underwater glider, and verified in field experiments in the Qiandao Lake, Zhejiang

Comparison of Veterans Affairs, Mayo, Brock classification models and radiologist diagnosis for classifying the malignancy of pulmonary nodules in Chinese clinical population

Background: Several classification models based on Western population have been developed to help clinicians to classify the malignancy probability of pulmonary nodules. However, the diagnostic performance of these Western models in Chinese population is unknown. This paper aimed to compare the diagnostic performance of radiologist evaluation of malignancy probability and three classification models (Mayo Clinic, Veterans Affairs, and Brock University) in Chinese clinical pulmonology patients. Methods: This single-center retrospective study included clinical patients from Tianjin Medical University Cancer Institute and Hospital with new, CT-detected pulmonary nodules in 2013. Patients with a nodule with diameter of 4-25 mm, and histological diagnosis or 2-year follow-up were included. Analysis of area under the receiver operating characteristic curve (AUC), decision curve analysis (DCA) and threshold of decision analysis was used to evaluate the diagnostic performance of radiologist diagnosis and the three classification models, with histological diagnosis or 2-year follow-up as the reference. Results: In total, 277 patients (286 nodules) were included. Two hundred and seven of 286 nodules (72.4%) in 203 patients were malignant. AUC of the Mayo model (0.77; 95% CI: 0.72-0.82) and Brock model (0.77; 95% CI: 0.72-0.82) were similar to radiologist diagnosis (0.78; 95% CI: 0.73-0.83; P=0.68, P=0.71, respectively). The diagnostic performance of the VA model (AUC: 0.66) was significantly lower than that of radiologist diagnosis (P=0.003). A three-class classifying threshold analysis and DCA showed that the radiologist evaluation had higher discriminatory power for malignancy than the three classification models. Conclusions: In a cohort of Chinese clinical pulmonology patients, radiologist evaluation of lung nodule malignancy probability demonstrated higher diagnostic performance than Mayo, Brock, and VA classification models. To optimize nodule diagnosis and management, a new model with more radiological characteristics could be valuable

A Subsolid Nodules Imaging Reporting System (SSN-IRS) for Classifying 3 Subtypes of Pulmonary Adenocarcinoma

It is essential to identify the subsolid nodules subtype preoperatively to select the optimal treatment algorithm. We developed and validated an imaging reporting system using a classification and regression tree model that based on computed tomography imaging characteristics (291 cases in training group, 146 cases in testing group). The model showed high sensitivity and accuracy of classification. Our model can help clinicians to make follow-up recommendations or decisions for surgery for clinical patients with a subsolid nodule

Distribution and Clinical Significance of Th17 Cells in the Tumor Microenvironment and Peripheral Blood of Pancreatic Cancer Patients

This study was designed to investigate the distribution of Th17 cells in the tumor microenvironment and peripheral blood of pancreatic cancer patients, its clinical significance, and the expression profile of Th17 cell-associated cytokines. The percentage of Th17 cells detected by flow cytometry analysis (FACS) was significantly higher in 46 pancreatic tumor tissues (5.28 ± 1.65%) compared with corresponding adjacent normal tissues (2.57 ± 0.83%) (P = 0.031). In addition, the percentage of Th17 cells was significantly higher in stage III-IV tumors than stage I-II tumors (P = 0.039). The percentage of Th17 cells in peripheral blood of 20 pancreatic cancer patients (3.99 ± 1.15%) was significantly higher than 15 healthy volunteers (1.98 ± 0.57%) (P = 0.027). Immunohistochemistry (IHC) was performed to detect IL-17+ cells in 46 pancreatic tumor tissues, as well as expression of CD34 in 24 tumor tissues. IL-17 was shown to mainly locate in cytoplasm, and the frequency of IL-17+ cells in tumor tissues (39/46) was higher than control (29/46). The presence of IL-17+ cells in tumor tissues was associated with tumor, node, and metastasis (TNM) stage, and lymph node metastasis (P = 0.012 and P = 0.009) but not with patient sex, age, tumor size, and histological grade (P > 0.05). Interestingly, distribution of Th17 cells in tumor tissues was positively correlated with microvessel density (MVD) (r = 0.86, P = 0.018). Furthermore, the median survival time of patients with high and low level of IL-17+ cells frequency was 14.5 and 18.5 months respectively (P = 0.023). The serum levels of Th17 cell-associated cytokines, IL-17 and IL-23 in 20 pancreatic patients detected by enzyme-linked immunosorbent assay (ELISA) were 69.2 ± 28.5 pg/mL and 266.5 ± 98.1 pg/mL, respectively, which were significantly higher than 15 healthy volunteers (P = 0.015 and P = 0.02). Moreover, levels of IL-17 and IL-23 were significantly higher in stage III-IV tumors than stage I-II tumors (P = 0.04 and P = 0.036). This study suggests that increase in Th17 cells frequency and its related cytokines levels in pancreatic tumor tissues may indicate involvement in the invasion and metastasis of pancreatic cancer, which may thereby affect patient prognosis. Therefore, Th17 cells and related cytokines may be served as important immune indicators for predicting the prognosis of pancreatic cancer patients

Myocardial production and release of MCP-1 and SDF-1 following myocardial infarction: differences between mice and man

<p>Abstract</p> <p>Background</p> <p>Stem cell homing to the heart is mediated by the release of chemo-attractant cytokines. Stromal derived factor -1 alpha (SDF-1a) and monocyte chemotactic factor 1(MCP-1) are detectable in peripheral blood after myocardial infarction (MI). It remains unknown if they are produced by, and released from, the heart in order to attract stem cells to repair the damaged myocardium.</p> <p>Methods</p> <p>Murine hearts were studied for expression of MCP-1 and SDF-1a at day 3 and day 28 following myocardial infarction to determine whether production is increased following MI. In addition, we studied the coronary artery and coronary sinus (venous) blood from patients with normal coronary arteries, stable coronary artery disease (CAD), unstable angina and MI to determine whether these cytokines are released from the heart into the systemic circulation following MI.</p> <p>Results</p> <p>Both MCP-1 and SDF-1a are constitutively produced and released by the heart. MCP-1 mRNA is upregulated following murine experimental MI, but SDF-1a is suppressed. There is less release of SDF-1a into the systemic circulation in patients with all stages of CAD including MI, mimicking the animal model. However MCP-1 release from the human heart following MI is also suppressed, which is the exact opposite of the animal model.</p> <p>Conclusions</p> <p>SDF-1a and MCP-1 release from the human heart are suppressed following MI. In the case of SDF-1a, the animal model appropriately reflects the human situation. However, for MCP-1 the animal model is the exact opposite of the human condition. Human observational studies like this one are paramount in guiding translation from experimental studies to clinical trials.</p

Realizing high-capacity all-solid-state lithium-sulfur batteries using a low-density inorganic solid-state electrolyte

Sulfur utilization in high-mass-loading positive electrodes is crucial for developing practical all-solid-state lithium-sulfur batteries. Here, authors propose a low-density inorganic solid-state electrolyte to improve the sulfur utilization in lab-scale Li-In||S all-solid-state cells

A Cross-Sectional Survey on Prevalence and Behaviour of Smokeless Tobacco Use Among Tobacco Users in China

Increasing tobacco control and public health awareness have increased smokers’ attempts to quit smoking. However, some smokers also seek alternative products claimed to pose less risks. The use of smokeless tobacco (ST) products may thus increase in some countries which are not traditionally ST markets. To provide a cross-sectional picture on ST usage in China, a survey was conducted from December 2019 to March 2020 in representative metropolitan cities (divided into three tiers by their populations and gross domestic product (GDP) sizes), from which 3,000 tobacco users and 801 ST users were randomly recruited to provide a snapshot of ST usage behaviour and other pertinent factors for Chinese tobacco users. The study included questionnaires designed to probe potential reasons behind ST use, usage habits, and nicotine dependence attributes. These questions were devised to cover the type of tobacco products used, users’ age, gender, city of residence, residence time, household monthly income, etc., and was supported by some verification questions. Mann-Whitney-analysis was used for significance analysis between different groups. The results showed that ST prevalence for Chinese tobacco users was around 2.1%. The proportion of exclusively ST use was about 8.99%, and the mean conversion time to habitual ST use was about three months. Demographic information such as the city tiers where ST users lived, their age, gender, educational and income levels appeared to correlate with ST use habits although more studies are needed to verify the observations. The fact that a small but measurable population of Chinese ST users exists has important implications for tobacco control. This study provides the first large-scale, single-time-point survey on Chinese ST user profiles, which may help the future research on tobacco control policy regarding ST products in China

Photochemical Reduction of Particle Bound Mercury in Atmospheric Aerosol Water

Particle bound mercury (PBM) deposition on the Earth’s surface threatens biota and humans. The photoreduction of PBM competes with deposition and thereby modifies global mercury cycling; yet, its pathway and mechanism remain poorly understood. Herein, we reveal the photoreduction process of PBM by comprehensively using field observation, mercury stable isotope analysis, and controlled experiment. We found the Δ199Hg values in wet haze episodes (0.34‰ ± 0.30‰) were significantly higher than those in clean periods (0.14‰ ± 0.19‰), majorly attributed to the elevated aerosol water content (AWC), which shifts the aerosol phase from the solid state to the liquid state, promoting soluble HgCl2 and HgBr2 photoreduction reactions. The carboxyl functional groups of water-soluble organic carbon (WSOC) were further identified as the crucial compounds that induce PBM photoreduction, whose reaction rates were ∼2 times higher than those of phenol and ketone ligands and 3–6 times higher than those observed in other atmospheric aqueous phases. Considering the ubiquitously distributed carboxyl ligands and significant positive Δ199Hg signals in the atmospheric aqueous phases, the PBM photoreduction mediated by carboxyl ligands is highlighted to significantly influence global mercury transformations, regional depositions, and isotopic compositions of atmospheric mercury pools