277 research outputs found
Esomeprazole improves the acidic microenvironment of epithelial ovarian cancer by inhibiting the expression of VATPase
Purpose: To determine the effect of esomeprazole on apoptosis of ovarian cancer cells and their sensitivity to paclitaxel, and the underlying mechanism.Methods: Human ovarian paclitaxel-resistant cancer cells were cultured in vitro, and treated with esomeprazole at doses of 50, 100 and 250 mol/L. Cell proliferation was determined using MTT assay. Paclitaxel-resistant cells were divided into control group, esomeprazole group, paclitaxel group, and esomeprazole + taxol group. Western blot was employed for the assay of protein levels of bcl-2, Bcl-xl, P-gp and V-ATPase, while BCECF-AM method was employed to determine changes in intracellular pH.Results: Esomeprazole significantly inhibited the proliferation of paclitaxel-resistant cells in a dosedependent manner. The half-maximal inhibitory concentration (IC50) value of esomeprazole + paclitaxel was significantly low, when compared with those of the other treatments (p < 0.05). Apoptosis was significantly higher in esomeprazole + paclitaxel group than in any other treatment group (p < 0.05). The expressions of Bcl-2 and P-gp in esomeprazole + paclitaxel group decreased significantly, relative to the corresponding values for other groups, while protein expression of bcl-xl was markedly increased. The intracellular pH value of esomeprazole + paclitaxel group was significantly lower than those for other treatment groups (p < 0.05).Conclusion: Esomeprazole improves the acidic microenvironment of epithelial ovarian cancer by inhibiting the expression of V-ATPase, and restores the sensitivity of ovarian cancer cells to paclitaxel by inhibiting their proliferation and apoptosis. This revelation may explain patients’ resistance topaclitaxel.
Keywords: Esomeprazole, V-ATPase, Apoptosis, Ovarian cancer, Taxol, Sensitivit
Robust model of fresh jujube soluble solids content with near-infrared (NIR) spectroscopy
A robust partial least square (PLS) calibration model with high accuracy and stability was established for the measurement of soluble solids content (SSC) of fresh jujube using near-infrared (NIR) spectroscopytechnique. Fresh jujube samples were collected in different areas of Taigu and Taiyuan cities, central China in 2008 and 2009. A partial least squares (PLS) calibration model was established based on the NIR spectra of 70 fresh jujube samples collected in 2008. A good calibration result was obtained with correlation coefficient (Rc) of 0.9530 and the root mean square error of calibration (RMSEC) of 0.3951 °Brix. Another PLS calibration model was established based on the NIR spectral of 180 samples collected in 2009; it resulted in the Rc of 0.8536 and the RMSEC of 1.1410 °Brix. It could be seen that the accuracy of established PLS models were different when samples harvested in different years were used for the model calibration. In order to improve the accuracy and robustness of model, different numbers (5, 10, 15, 20, 30 and 40) of samples harvested in 2008 were added to the calibration sample set of the model with samples harvested in 2009, respectively. The established PLS models obtained Rc with the range of 0.8846 to 0.8893 and RMSEC with the range of 1.0248 to 0.9645 °Brix. The obtained results werebetter than the result of the model which was established only with samples harvested in 2009. Moreover, the models established using different numbers of added samples had similar results. Therefore, it was concluded that adding samples from another harvest year could improve the accuracy and robustness of the model for SSC prediction of fresh jujube. The overall results proved that the consideration of samples from different harvest places and years would be useful for establishing an accuracy and robustness spectral model.Keywords: Near-infrared (NIR) spectroscopy, Huping jujube, soluble solids content (SSC), partial least squares (PLS), accuracy, stabilit
Efficient and durable uranium extraction from uranium mine tailings seepage water via a photoelectrochemical method
Current photocatalytic uranium (U) extraction methods have intrinsic obstacles, such as the recombination of charge carriers, and the deactivation of catalysts by extracted U. Here we show that, by applying a bias potential on the photocatalyst, the photoelectrochemical (PEC) method can address these limitations. We demonstrate that, owing to efficient spatial charge-carriers separation driven by the applied bias, the PEC method enables efficient and durable U extraction. The effects of multiple operation conditions are investigated. The U extraction proceeds via single-step one-electron reduction, resulting in the formation of pentavalent U, which can facilitate future studies on this often-overlooked U species. In real seepage water the PEC method achieves an extraction capacity of 0.67 gU m(-3).h(-1) without deactivation for 156 h continuous operation, which is 17 times faster than the photocatalytic method. This work provides an alternative tool for U resource recovery and facilitates future studies on U(V) chemistry
Co-making the future: judges’ insights on transdisciplinary creativity and global collaboration in the China-U.S. young maker competition
This paper examines the future of maker education through an analysis of feedback from judges in the China-U.S. Young Maker Competition. Drawing on inputs from 36 judges from diverse backgrounds in academia, industry, and sponsoring companies, the study uses thematic analysis of interviews, feedback, and focus group discussions to uncover key educational trends. It highlights critical themes such as transdisciplinary creativity, real-world application, sustainability, cross-cultural collaboration, and innovation mindset. The research reveals a trend towards integrating various academic fields to boost creative problem-solving and application in real-life scenarios. Sustainability is identified as a crucial component, pointing to the need for environmentally aware education. The study also emphasizes the importance of cross-cultural collaboration for global interconnectedness and adaptive problem-solving, alongside fostering a continuous innovation mindset in students. Concluding with future directions for maker education, the paper advocates for an experiential, inclusive, and forward-looking educational approach. It underscores the importance of a broad curriculum that integrates entrepreneurial skills, promotes lifelong learning, and enhances global connectivity. This study provides insights for educators, policymakers, and practitioners, offering a streamlined roadmap for advancing maker education in a rapidly evolving global context
Large expert-curated database for benchmarking document similarity detection in biomedical literature search
Document recommendation systems for locating relevant literature have mostly relied on methods developed a decade ago. This is largely due to the lack of a large offline gold-standard benchmark of relevant documents that cover a variety of research fields such that newly developed literature search techniques can be compared, improved and translated into practice. To overcome this bottleneck, we have established the RElevant LIterature SearcH consortium consisting of more than 1500 scientists from 84 countries, who have collectively annotated the relevance of over 180 000 PubMed-listed articles with regard to their respective seed (input) article/s. The majority of annotations were contributed by highly experienced, original authors of the seed articles. The collected data cover 76% of all unique PubMed Medical Subject Headings descriptors. No systematic biases were observed across different experience levels, research fields or time spent on annotations. More importantly, annotations of the same document pairs contributed by different scientists were highly concordant. We further show that the three representative baseline methods used to generate recommended articles for evaluation (Okapi Best Matching 25, Term Frequency-Inverse Document Frequency and PubMed Related Articles) had similar overall performances. Additionally, we found that these methods each tend to produce distinct collections of recommended articles, suggesting that a hybrid method may be required to completely capture all relevant articles. The established database server located at https://relishdb.ict.griffith.edu.au is freely available for the downloading of annotation data and the blind testing of new methods. We expect that this benchmark will be useful for stimulating the development of new powerful techniques for title and title/abstract-based search engines for relevant articles in biomedical research.Peer reviewe
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
Novel phosphor GdY2SbO7 co-dope with Eu3+ and Bi3+ for optical thermometer
A series of GdY2SbO7:Bi3+, Eu3+ phosphors were prepared using the conventional solid-state reaction. In this study, the photoluminescence properties and temperature sensitivity of the samples were investigated. When Bi3+ and Eu3+ were codoped into GdY2SbO7, the intensity of Bi3+ decreased with increasing Eu3+ concentration, indicating a potential energy transfer from Bi3+ to Eu3+. To examine the temperature sensitivity of the sample, its emission spectrum was investigated in the range of 300–500 K. Based on different temperature dependences of Bi3+ and Eu3+, the relative sensitivity (Sr) and absolute sensitivity (Sa) of the samples were calculated using the fluorescence intensity ratio (FIR) and thermochromic methods. In FIR modes, Sr based on IEu3+/IBi3+ reached 1.26 % K−1 at 500 K, while Sr on double excitation method reached 1.36 % K−1 at 340 K. In addition, according to the thermochromic properties of GdY2SbO7:Bi3+, Eu3+ phosphor, the temperature-sensing ability of the sample was investigated, and Sr reached a maximum value of 0.5996 % K−1 at 300 K
Numerical Simulation of Non-Spherical Submicron Particle Acceleration and Focusing in a Converging–Diverging Micronozzle
Submicron particles transported by a Laval-type micronozzle are widely used in micro- and nano-electromechanical systems for the aerodynamic scheme of particle acceleration and focusing. In this paper, the Euler–Lagrangian method is utilized to numerically study non-spherical submicron particle diffusion in a converging–diverging micronozzle flow field. The influence of particle density and shape factor on the focusing process is discussed. The numerical simulation shows how submicron particle transporting with varying shape factors and particle density results in different particle velocities, trajectories and focusing in a micronozzle flow field. The particle with a larger shape factor or larger density exhibits a stronger aerodynamic focusing effect in a supersonic flow field through the nozzle. In the intersection process, as the particle size increases, the position of the particle trajectory intersection moves towards the throat at first and then it moves towards the nozzle outlet. Moreover, the influence of the thermophoretic force of the submicron particle on the aerodynamic focusing can be ignored. The results will be beneficial in technological applications, such as micro-thrusters, microfabrication and micro cold spray
Synthesis of Bimetallic PdAg Nanoparticles and Their Electrocatalytic Activity toward Ethanol
Palladium-based bimetallic nanoparticles (NPs) have been studied as important electrocatalysts for energy conversion due to their high electrocatalytic performance and the less usage of the noble metal. Herein, well-dispersed PdAg NPs with uniform size were prepared via oil bath accompanied with the hydrothermal method. The variation of the Ag content in PdAg NPs changed the lattice constant of the face-centered cubic alloy nanostructures continuously. The Pd/Ag molar ratio in the PdAg alloy NPs affected their size and catalytic activity toward ethanol electrooxidation. Experimental data showed that PdAg NPs with less Ag content exhibited better electrocatalytic activity and durability than pure Pd NPs owing to both the small size and the synergistic effect. PdAg-acac-4 with the Pd/Ag molar ratio of 4 : 1 in the start system possessed the highest catalytic current density of 2246 mA/mg for the electrooxidation of ethanol. The differences in the morphology and electrocatalytic activity of the as-made PdAg NPs have been discussed and analyzed
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