Analysis of intercellular communication in the osteosarcoma microenvironment based on single cell sequencing data.

Osteosarcoma (OS) is the most common primary bone cancer in children and young adults, patient survival rates have not improved in recent decades. To further understand the interrelationship between different cell types in the tumor microenvironment of osteosarcoma, we comprehensively analyzed single-cell sequencing data from six patients with untreated osteosarcoma. Nine major cell types were identified from a total of 46,046 cells based on unbiased clustering of gene expression profiles and canonical markers. Osteosarcoma from different patients display heterogeneity in cellular composition. Myeloid cells were the most commonly represented cell type, followed by osteoblastic and TILs. Copy number variation (CNV) results identified amplifications and deletions in malignant osteoblastic cells and fibroblasts. Trajectory analysis based on RNA velocity showed that osteoclasts in the OS microenvironment could be differentiated from myeloid cells. Furthermore, we explored the intercellular communications in OS microenvironment and identified multiple ligand-receptor pairs between myeloid cells, osteoblastic cells and their cells, including 21 ligand-receptor pair genes that significantly associated with survival outcomes. Importantly, we found chemotherapy may have an effect on cellular communication in the OS microenvironment by analyzing single-cell sequencing data from seven primary osteosarcoma patients who received chemotherapy. We believe these observations will improve our understanding of potential mechanisms of microenvironment contributions to OS progression and help identify potential targets for new treatment development in the future.

Dynamic stability and optimal control of SIS q I q RS epidemic network.

We develop a complex network-based SIS q I q RS model, calculate the threshold R 0 of infectious disease transmission and analyze the stability of the model. In the model, three control measures including isolation and vaccination are considered, where the isolation is structured in isolation of susceptible nodes and the isolation of infected nodes. We regard these three kinds of controls as time-varying variables, and obtain the existence and the solution of the optimal control by using the optimal control theory. With regard to the stability of the model, sensitivity analysis of the parameters and optimal control, we carry out numerical simulations. From the simulation results, it is obvious that when the three kinds of controls exist simultaneously, the scale and cost of the disease are minimal. Finally, we fit the real data of COVID-19 to the numerical solution of the model.

Fractional dynamic analysis and optimal control problem for an SEIQR model on complex networks.

A fractional order susceptible-exposed-infected-quarantined-recovered model is established on the complex networks. We calculate a specific expression for the basic reproduction number R0, prove the existence and uniqueness with respect to the solution, and prove the Ulam-Hyers stability of the model. Using the Latin hypercube sampling-partial rank correlation coefficient method, the influence of parameters on the R0 is analyzed. Based on the results of the analysis, the optimal control of the model is investigated as the control variables with vaccination rate and quarantine rate applying Pontryagin's minimum principle. The effects of α, degree of nodes, and network size on the model dynamics are simulated separately by the prediction correction method.

Ventriculoperitoneal shunt malfunction diagnosis based on substance dilution.

OBJECTIVE: Current methods for the diagnosis of ventriculoperitoneal (VP) shunt malfunction lack specific standards; therefore, it may be missed or misdiagnosed. Hence, providing a reliable diagnostic method will help improve the accuracy of preoperative decision-making. Therefore, the aim of the study was to provide a new method for the diagnosis of VP shunt malfunction. METHODS: After in vitro testing, we enrolled a total of 12 patients with VP shunt malfunction. Before revision surgery, 0.1 mL of a 5% sodium valproate (SV) solution was injected into the reservoir; 0.1 mL of the cerebrospinal fluid (CSF) was withdrawn 20 minutes later from the reservoir to measure the SV concentration. The process was repeated on the seventh day after surgery and compared with the preoperative results. RESULTS: The mean ±â€Šstandard deviation preoperative SV concentration in the cerebrospinal fluid was greater than the postoperative concentration (5967.8 ±â€Š1281.3 vs 391.1 ±â€Š184.6 µg/mL, P = .001). CONCLUSION: The proposed method is a reliable, safe, and relatively simple alternative for the diagnosis of VP shunt malfunction and further provides a reference for treatment.

Effect of oxygen vacancies on the laser-induced damage resistance of Y0.26Hf0.74Ox thin films.

The influence of the oxygen sub-stoichiometry on the femtosecond laser-induced damage resistance of Y0.26Hf0.74Ox films was investigated in this work. Photoluminescence (PL) spectroscopy was applied to analyze the various states of oxygen vacancies (V(O)), and laser-induced damage measurement was performed using a single 500 fs pulse laser at a wavelength of 1030 nm. Based on the PL spectra, a probable band gap structure with different defect energy levels was obtained, which is significant in explaining an observed inverse correlation between the laser-induced damage threshold (LIDT) and the concentration of V(O). The crystallization and the refractive index, which were previously found to be crucial factors in laser-induced damage resistance of optical thin films, are also closely dependent on the amount of induced oxygen vacancies.