Oscillation criteria for first-order impulsive differential equations with positive and negative coefficients

AbstractSome sufficient conditions are obtained for oscillation of all solutions of the first-order impulsive differential equation with positive and negative coefficients[x(t)-R(t)x(t-r)]′+P(t)x(t-τ)-Q(t)x(t-σ)=0,τ⩾σ>0,t⩾t0,x(tk+)=Ik(x(tk)),k=1,2,….Our results improve the known results in the literature

Do young CEOs matter for corporate digital transformation?

This paper investigates the empirical relation between CEO age and corporate digital transformation. Using a sample of Chinese listed firms between 2007 and 2022, we find that younger CEOs exhibit a higher propensity to engage in digital transformation when compared to older counterparts. We pinpoint two key driving factors behind this phenomenon: CEOs’ motivation to establish a good reputation and their willingness to embrace failure. Furthermore, our heterogeneity tests show that the negative relation between CEO age and digital transformation does not vary with firms’ state ownership, but is more pronounced among firms with fewer financial constraints. Overall, our finding contributes to the growing body of literature examining the role of managerial traits in corporate digital transformation

S_I_LSTM: stock price prediction based on multiple data sources and sentiment analysis

Stocks price prediction is a current hot spot with great promise and challenges. Recently, there have been many stock price prediction methods. However, the prediction accuracy of these methods is still far from satisfactory. In this paper, we propose a stock price prediction method that incorporates multiple data sources and the investor sentiment, which can be called S_I_LSTM. Firstly, we crawl multiple data sources on the Internet and preprocess them respectively. These data involve stock historical data, technical indicators, and non-traditional data sources, such as stock posts and financial news. Then, we use the sentiment analysis method based on convolutional neural network for the non-traditional data, which can calculate the investors' sentiment index. Finally, we combine sentiment index, technical indicators and stock historical transaction data as the feature set of stock price prediction and adopt the long short-term memory network for predicting the China Shanghai A-share market. The experiments show that the predicted stock closing price is closer to the true closing price than the single data source, and the mean absolute error can achieve 2.386835, which is better than traditional methods. We verified the effectiveness on the real data sets of five listed companies

INTERNAL FRICTION AND ELASTIC MODULUS OF AuCd IN THE VICINITY OF MARTENSITIC TRANSFORMATION

The internal friction and modulus related to martensitic transformation in 4 kinds of AuCd alloys were measured at low and high frequencies. The heights of the Q-1 peaks (at 49 KHz and 1 Hz) increased significantly in successive measuring runs, whereas no change was observed in modulus variation. It was associated with the increase of interfaces of parent-martensite by the metallographic examination. The low frequency damping was confirmed as a static hysteresis loss and the formation of the Q-1 peak was explained in terms of the localized soft mode theory and dislocation damping. The high frequency damping has the component contributed by viscous motion of dislocation. Otherwise, we found a Q-1 peak during isothermal transition and a broad Q-1 peak appearing in the temperature range of premartensitic transformation

Predicting skip metastasis in lateral lymph nodes of papillary thyroid carcinoma based on clinical and ultrasound features

BackgroundSkip metastasis in papillary thyroid cancer (PTC), defined as lateral lymph node metastasis (LLNM) without the involvement of central lymph node metastasis (CLNM), is generally unpredictable. Our study aimed to develop a model to predict skip metastasis by using clinicopathological and ultrasound factors of PTC.MethodsWe retrospectively reviewed the medical records of patients who underwent total thyroidectomy and central lymph node dissection (CLND) plus lateral lymph node dissection (LLND) between January 2019 and December 2021 at the First Affiliated Hospital of Soochow University. Furthermore, univariate and multivariate analyses assessed the clinical and ultrasound risk factors. Receiver operating characteristic (ROC) curves were used to find the optimal cut-off values for age and dominant nodule diameter. Multivariate logistic regression analysis results were used to construct a nomogram and were validated internally.ResultsIn all patients, the skip metastasis rate was 15.4% (41/267). Skip metastasis was more frequently found in patients with a tumour size ≤10 mm (OR 0.439; P = 0.033), upper tumour location (OR 3.050; P=0.006) and fewer CLNDs (OR 0.870; P = 0.005). After analysing the clinical and ultrasound characteristics of the tumour, five factors were ultimately associated with lateral lymph node skip metastasis and were used to construct the model. These factors were an age >40 years, tumour diameter <9.1 mm, upper tumour location, non-smooth margin and extrathyroidal extension. The internally evaluated calibration curves indicated an excellent correlation between the projected and actual skip metastasis probability. The nomogram performed well in discrimination, with a concordance index of 0.797 (95% CI, 0.726 to 0.867).ConclusionsThis study screened for predictors of skip metastasis in PTC and established a nomogram that effectively predicted the risk of potential skip metastasis in patients preoperatively. The method can predict and distinguish skip metastases in PTC in a simple and inexpensive manner, and it may have future therapeutic utility

Inhibitory effects of the nanoscale lysate derived from xenogenic dental pulp stem cells in lung cancer models

Abstract Background Lung cancer is a highly prevalent malignancy and has the highest mortality rate among all tumors due to lymph node metastasis. Bone marrow and umbilical cord-derived mesenchymal stem cells (MSCs) have demonstrated tumor-suppressive effects on lung cancer. This study investigated the effects of DPSC lysate on proliferation, apoptosis, migration and invasion of cancer cells were studied in vivo and in vitro. Methods The proliferation, apoptosis, and migration/metastasis were evaluated by cell counting kit-8 assay, Annexin-V and propidium iodide staining, and the transwell assay, respectively. The expression levels of apoptosis-, cell cycle-, migration-, and adhesion-related mRNA and proteins were measured by qRT-PCR and western blot. The level and mRNA expression of tumor markers carcino embryonic antigen (CEA), neuron-specific enolase (NSE), and squamous cell carcinoma (SCC) were measured by Enzyme-linked immunosorbent assay (ELISA) and qRT-PCR. Finally, a tumor-bearing mouse model was constructed to observe the tumor-suppressive effect of DPSC lysate after intraperitoneal injection. Results DPSC lysate decreased the viability of A549 cells and induced apoptosis in lung cancer cells. Western blot confirmed that levels of Caspase-3, Bax, and Bad were increased, and Bcl-2 protein levels were decreased in A549 cells treated with DPSC lysate. In addition, DPSC lysate inhibited the migration and invasion of A549 cells; downregulated key genes of the cell cycle, migration, and adhesion; and significantly suppressed tumor markers. Xenograft results showed that DPSC lysate inhibited tumor growth and reduced tumor weight. Conclusions DPSC lysate inhibited proliferation, invasion, and metastasis; promoted apoptosis in lung cancer cells; and suppressed tumor growth- potentially providing a cell-based alternative therapy for lung cancer treatment. Graphical Abstrac