Positive Periodic Solutions of Nicholson-Type Delay Systems with Nonlinear Density-Dependent Mortality Terms

This paper is concerned with the periodic solutions for a class of Nicholson-type delay systems with nonlinear density-dependent mortality terms. By using coincidence degree theory, some criteria are obtained to guarantee the existence of positive periodic solutions of the model. Moreover, an example and a numerical simulation are given to illustrate our main results

Compartmentalization of incompatible reagents within Pickering emulsion droplets for one-pot cascade reactions

It is a dream that future synthetic chemistry can mimic living systems to process multistep cascade reactions in a one-pot fashion. One of the key challenges is the mutual destruction of incompatible or opposing reagents, for example, acid and base, oxidants and reductants. A conceptually novel strategy is developed here to address this challenge. This strategy is based on a layered Pickering emulsion system, which is obtained through lamination of Pickering emulsions. In this working Pickering emulsion, the dispersed phase can separately compartmentalize the incompatible reagents to avoid their mutual destruction, while the continuous phase allows other reagent molecules to diffuse freely to access the compartmentalized reagents for chemical reactions. The compartmentalization effects and molecular transport ability of the Pickering emulsion were investigated. The deacetalization–reduction, deacetalization–Knoevenagel, deacetalization–Henry and diazotization–iodization cascade reactions demonstrate well the versatility and flexibility of our strategy in processing the one-pot cascade reactions involving mutually destructive reagents

Trade Liberalization, domestic input and sustainability of agricultural TFP growth: A new Perspective Based on TFP growth structure

AbstractAs one of the fundamental ways to solve the food security and promote farmers’ income, agriculture Total Factor Productivity (TFP) growth has attached a great concern which is examined in a vast literature. However, there is little work that examines sustainability of the growth, which is more significant for future development of agricultural sector. Moreover, whether trade openness and domestic investment policy which are used to promote the agricultural TFP growth also could play a great role in the sustainability of the agricultural TFP growth is rarely examined. We estimate and decompose China's agricultural TFP using Data Envelopment Analysis (DEA), finding that technical change is the main source of China's agricultural TFP growth since 1978, favoring that TFP growth is lack of sustainability. In addition, using two-stage estimation procedure, we make an empirical analysis about the impact of trade openness and domestic input on TFP structure. Results show that trade openness and agricultural infrastructure is narrowing the gap between the two sources, while agricultural scientific investment is just the opposite. Therefore an in-depth trade openness and agricultural infrastructure are needed favoring the growth of China's agriculture, while agricultural scientific investment should be conducted after a higher level of trade openness and agricultural infrastructure

Evodiamine induces extrinsic and intrinsic apoptosis of ovarian cancer cells via the mitogen-activated protein kinase/phosphatidylinositol-3-kinase/protein kinase B signaling pathways

AbstractObjectiveTo explore the effects of evodiamine on ovarian cancer cells and the mechanisms underlying such effects.MethodsHuman ovarian cancer cells HO-8910PM were treated with evodiamine at 0, 1.25, 2.5, and 5 μM for 1-4 d. 3-(4,5-Dimethiylthiazol2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay was used to detect the growth inhibition rate of evodiamine-treated HO-8910PM cells. The cell cycle was observed via propidium iodide (PI) staining. Apoptosis induction was assessed via Annexin V-fluorescein isothiocyanate/propidium iodide (Annexin V-FITC/PI) double staining assay. To verify the mechanism of apoptosis, caspase-dependent apoptotic pathway-related protein was detected by Western blot analysis. The expression levels of mitogen-activated protein kinase (MAPK) and/or phosphatidylinositol-3-kinase (PI3K)/protein kinase B (Akt) pathway-related proteins were also investigated.ResultsEvodiamine significantly inhibited the proliferation of HO-8910PM cells in a dose- and time-dependent manner. Evodiamine induced G2/M arrest with an increase of cyclin B1 level, and promoted cell apoptosis with a decrease of B cell lymphoma/lewkmia-2 (Bcl-2) and an increase of Bcl-2-associated X protein (Bax) level. In addition, evodiamine treatment led to the activation of caspase-8, caspase-9, and caspase-3 and the cleavage of poly (ADP-ribose)-polymerase (PARP). Evodiamine targeted the MAPK and/or PI3K/Akt pathways by reducing the expression and activity of PI3K, Akt, and extracellular signal-regulated kinase mitogen-activated protein kinase (ERK1/2 MAPK) and the activity of p38 MAPK.ConclusionEvodiamine can inhibit the growth of ovarian cancer cells by G2/M arrest and intrinsic and extrinsic apoptosis. In addition, evodiamine-induced PI3K/Akt, ERK1/2 MAPK, and p38 MAPK signaling may be involved in cell death

Diurnal fluctuations in seawater pCO2 amplify the negative effects of ocean acidification on the biotic performance of the calcifying macroalga Halimeda opuntia

Although the adverse effects of increasing atmospheric CO2-induced ocean acidification (OA) on marine calcifying macroalgae have been widely reported, there are limited studies on how daily fluctuations in pCO2 (pH) within shallow ecosystems influence the growth and physiological performance of these calcifiers. Therefore, a 42-day laboratory mimetic experiment to determine how growth, biological performance and related carbon and nitrogen metabolic products of the calcifying macroalga, Halimeda opuntia are generated in response to fluctuating pCO2 under OA conditions (1200 ppmv) was performed. The results of present study showed that the adverse effects of OA were more determined by the adverse influence of elevated acidity (H+) on growth rates, calcification, photosynthesis and the related biotic performance of H. opuntia compared with the positive effects that higher CO2 provided. Moreover, diurnal fluctuations in pCO2 levels [with higher (nearly 8.10) and lower pH (nearly 7.40) values during day and night times, respectively] have amplified these negative influences on H. opuntia. To mitigate elevated pCO2-related stress, higher contents of free amino acids and proline were highly secreted and likely linked to protecting the integrity of algal cellular structures. The above results contribute to increasing our understanding of the biological consequences of pCO2 (pH) variability on calcifying Halimeda species and their physiological plasticity in response to further oceanic pCO2 changes

Efficacy of EGFR-TKI therapy in patients with brain metastases from non-small-cell lung cancer: A metaanalysis

Purpose: This meta-analysis aimed to systematically evaluate the efficacy of tyrosine kinase inhibitors of epidermal growth factor receptor (EGFR-TKIs) for patients with brain metastases (BM) from nonsmall- cell lung cancer (NSCLC), and to compare this treatment modality to chemotherapy or radiotherapy.Methods: PubMed, EMBASE (OvidSP), the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science and ASCO Annual Meeting Abstracts were searched. Controlled clinical studies that compared the efficacy of EGFR-TKIs with chemotherapy or radiotherapy for NSCLC patients with BM were included in the analysis. Efficacy indicators included overall survival (OS), local progression-free survival (LPFS) and objective response rate (ORR).Results: The final sample consisted of 24,637 NSCLC patients with BM from 11 clinical studies. In primary efficacy analysis, it was found that EGFR-TKIs were significantly superior to chemotherapy or radiotherapy in terms of ORR (odds ratio (OR) = 2.10, p = 0.035), OS (hazard ratio (HR) = 0.78, p = 0.011) and LPFS (HR = 0.60, p < 0.001).Conclusion: Among the patients with BM from NSCLC, EGFR-TKIs exhibit a therapeutic advantage over chemotherapy or radiotherapy, which is reflected in the elevation of ORR and improvement in OS and LPFS.Keywords: Brain metastasis, Non-small-cell lung cancer (NSCLC), Protein kinase Inhibitors, Epidermal growth factor, Meta-analysi