Hard-label black-box textual adversarial attacks present a highly challenging task due to the discrete and non-differentiable nature of text data and the lack of direct access to the model's predictions. Research in this issue is still in its early stages, and the performance and efficiency of existing methods has potential for improvement. For instance, exchange-based and gradient-based attacks may become trapped in local optima and require excessive queries, hindering the generation of adversarial examples with high semantic similarity and low perturbation under limited query conditions.
View Article and Find Full Text PDFWe investigate the effects of uniform viscosity gradients on the spontaneous oscillations of an elastic, active filament in viscous fluids. Combining numerical simulations and linear stability analysis, we demonstrate that a viscosity gradient increasing from the filament's base to tip destabilises the system, facilitating its self-oscillation. This effect is elucidated through a reduced-order model, highlighting the delicate balance between destabilising active forces and stabilising viscous forces.
View Article and Find Full Text PDFA natural killer (NK)-92 cell membrane-camouflaged mesoporous MnO-enveloped Au@Pd (Au@Pd@MnO) nanoparticles (denoted as APMN NPs)-based versatile biomimetic theranostic nanoplatform was developed for magnetic resonance (MR) imaging-guided multimodal synergistic antitumor treatments. In this core-shell nanostructure, an Au@Pd core induced near-infrared (NIR)-activatable hyperthermal effects and nanozyme catalytic activity, while a mesoporous MnO shell not only afforded a high drug-loading capability, tumor microenvironment (TME)-triggered MR imaging and drug release, but also endowed catalase-, glutathione peroxidase-, and Fenton-like activities. Furthermore, the NK-92 cell membrane camouflaging endowed the NPs with enhanced tumor-targeting capability, immune escape function, and membrane protein-mediated tumoral uptake property.
View Article and Find Full Text PDFTumor hypoxic microenvironment can reduce the therapeutic effects of chemotherapy, radiotherapy, photodynamic therapy, immunotherapy, etc. It is also a potential source of tumor recurrence and metastasis. A biomimetic nanosystem based on zeolitic imidazolate framework 8 (ZIF8), which had multifunctions of hypoxia relief, chemotherapy, and photothermal therapy, was established to improve tumor hypoxic microenvironment and overcome the corresponding therapeutic resistance.
View Article and Find Full Text PDFFlagellated bacteria swim by rotating a bundle of helical flagella and commonly explore the surrounding environment in a "run-and-tumble" motility mode. Here, we show that the upcoming flow could impact the bacterial run-and-tumble behavior by affecting the formation and dispersal of the flagellar bundle. Using a dual optical tweezers setup to trap individual bacteria, we characterized the effects of the imposed fluid flow and cell body rotation on the run-and-tumble behavior.
View Article and Find Full Text PDFIn this study, a new type of β-1,3-d-glucan porous microcapsule (GPM)-enveloped and folate conjugated chitosan-functional liposome (FCL), FCL@GPM, was developed for the potential oral co-delivery of chemotherapeutic drugs and quantum dots (QDs) with facilitated drug absorption and antitumor efficacy. In this dual-particulate system, multiple FCLs serve as the cores for effective loading, folate-mediated tumor-targeting, facilitated intracellular accumulation, and pH-responsive controlled release of chemotherapeutic agents, while a GPM acts as the shell for affording macrophage-mediated tumor selectivity. Gefitinib (GEF) was selected as a chemotherapeutic agent, while acid degradable ZnO QDs were selected due to their dual role as an anticancer agent for synergistic chemotherapy and as a fluorescent probe for potential cancer cellular imaging.
View Article and Find Full Text PDFCuY catalysts were prepared by high temperature anhydrous interaction between NHY zeolite and copper(ii) acetylacetonate Cu(acac) and the activities were measured for the oxidative carbonylation of methanol to dimethyl carbonate under atmospheric pressure. The bulk and surface properties of the as-prepared catalyst were characterized by XRD, H-TPR and XPS techniques. The activation atmosphere of the CuY catalyst and the testing temperature of the catalytic activity was systematically studied.
View Article and Find Full Text PDFHigh spatiotemporal resolution fine particulate matter (PM) simulations can provide important exposure data for the assessment of long-term and short-term health effects. Satellite-based aerosol optical depth (AOD) data, meteorological data, and topographic data have become key variables for PM estimation. In this study, a random forest model was developed and used to estimate the highest resolution (0.
View Article and Find Full Text PDFIn this study, a new kind of folic acid (FA)-conjugated and chitosan (CS)-coated poloxamer 407 (P407)/poly(lactic--glycolic acid) (PLGA) nanoparticles (NPs), FCPP NPs, were prepared, and further micro-encapsulated by carboxymethyl β-glucan microcapsules (MCs) to produce a multifunctional system of NPs embedded in MCs (NEMs) for potential lung tumor-targeted delivery of gefitinib. The prepared gefitinib-loaded FCPP (GFB/FCPP) NPs showed a hydrodynamic diameter of 255.4 ± 14.
View Article and Find Full Text PDFEvid Based Complement Alternat Med
October 2017
Chinese medicine has been used for Alzheimer's disease (AD) treatment for thousands of years with more effective and fewer side effects. Therefore, developing effective potential candidates from Chinese medicine against AD would be considered as critical and efficient therapy for AD treatment. This study was designed to evaluate the neuronal protective effect of fraction n-butanol (NB) of Radix Notoginseng on A-induced PC12 cells, explore the effect of the tested fraction on spatial learning and memory, and characterize the impacts of fraction NB on antioxidant enzymes, A production, and APP and BACE1 expressions.
View Article and Find Full Text PDFQ10 is a powerful antioxidant often used in medical nutritional supplements for cancer treatment. This study determined whether Q10 could effectively prevent cardio-toxicity caused by doxorubicin treatment. Four week old SD rats were segregated into groups namely control, doxorubicin group (challenged with doxorubicin), Dox + Q10 group (with doxorubicin challenge and oral Q10 treatment), and Q10 group (with oral Q10 treatment).
View Article and Find Full Text PDFEnviron Sci Pollut Res Int
June 2015
Epidemiological studies have widely demonstrated association between ambient ozone and mortality, though controversy remains, and most of them only use a certain metric to assess ozone levels. However, in China, few studies have investigated the acute effects of ambient ozone, and rare studies have compared health effects of multiple daily metrics of ozone. The present analysis aimed to explore variability of estimated health effects by using multiple temporal ozone metrics.
View Article and Find Full Text PDFDust intake is an important source of children's metal exposure. To explore the contamination level and health risk of toxic metals in kindergartens, surface dust samples were collected with self-made sampler in representative kindergartens in urban Beijing and concentrations of Pb, Hg, Cd, As were analyzed. It was found that Cd, Hg, Pb accumulated in indoor dust in different degrees with a significant seasonal variation.
View Article and Find Full Text PDFTo investigate short-term effects of ambient ozone exposure on mortality in Chinese cities, we conducted a meta-analysis of 10 effect estimates of 5 short-term studies, which reported associations between ambient ozone and mortality in Chinese mainland cities. And we estimated pooled effects by non-accidental mortality, cardiovascular mortality, and respiratory mortality. Combined estimates and their 95%CI were tested by RevMan 5, and Funnel plots were used for the bias analysis.
View Article and Find Full Text PDFParticles with aerodynamic diameters <10 microm (PM(10)) and particles with aerodynamic diameters <2.5 microm (PM(2.5)) were sampled during summer 2006 in Beijing and mass concentrations, water-soluble ionic compounds concentrations, and acidic buffer capacity were analyzed.
View Article and Find Full Text PDFSecondary organic aerosols (SOA) is an important component of the atmospheric particle pollution, thus, determining the status and sources of SOA pollution is the premise of deeply understanding the occurrence, development law and the influence factors of the atmospheric particle pollution. Based on the pollution sources and meteorological data of Pearl River Delta region, the study used the two-dimensional model coupled with SOA module to stimulate the status and source of SOA pollution in regional scale. The results show: the generation of SOA presents obvious characteristics of photochemical reaction, and the high concentration appears at about 14:00; SOA concentration is high in some areas of Guangshou and Dongguan with large pollution source-emission, and it is also high in some areas of Zhongshan, Zhuhai and Jiangmen which are at downwind position of Guangzhou and Dongguan.
View Article and Find Full Text PDFHuan Jing Ke Xue
November 2009
Rain and atmospheric particle samples were collected in the rural area of Taian and Shenzhen in 2007, respectively. Rain sampling was carried out during the precipitation process and several samples were got from the beginning of one precipitation to the end. The chemical character changes during precipitation and the changes of concentration of particles before and after rain were studied in this research to understand the contribution of particles on the rain chemical character and the rain-out effect for particles.
View Article and Find Full Text PDFSci China C Life Sci
October 2008
Trachea is the unique passage for air to flow in and out. Its tone is of importance for the respiration system. However, investigation on how tracheal tone changes due to asthma is limited.
View Article and Find Full Text PDFThe no-load state and zero-stress state of the normal rat trachea were analyzed. It was found that there exist compressive residual strains in the inner wall region of the rat trachea and tensile residual strains in the outer wall region. The fact that the opening angle of the rat trachea cut at the cartilaginous region is significantly larger than that cut at the muscular portion shows that residual strains exist mainly in the muscular region in the rat trachea.
View Article and Find Full Text PDFA modified two-dimensional Eulerian air quality model was used to simulate both the gaseous and particulate pollutant concentrations during October 21-24, 2004 in the Pearl River Delta (PRD) region, China. The most significant improvement to the model is the added capability to predict the secondary organic aerosols (SOA) concentrations because of the inclusion of the SOA formation chemistry. The meteorological input data were prepared using the CALMET meteorological model.
View Article and Find Full Text PDFEnviron Sci Technol
February 2007
Bromine gas was evaluated for converting elemental mercury (Hg0) to oxidized mercury, a form that can readily be captured by the existing air pollution control device. The gas-phase oxidation rates of Hg0 by Br2 decreased with increasing temperatures. SO2, CO, HCl, and H2O had insignificant effect, while NO exhibited a reverse course of effect on the Hg0 oxidation: promotion at low NO concentrations and inhibition at high NO concentrations.
View Article and Find Full Text PDFThis study examined the concentrations of carbon monoxide, carbon dioxide, TVOC, TSP, PM(10), PM(2.5), PM(1), benzene, toluene and xylene in passenger cars of the Beijing Ground Railway Transit System (Line No. 13).
View Article and Find Full Text PDFJ Environ Sci (China)
August 2005
Twenty-three kinds of typical plants in Xishuangbanna, the tropical area of southwestern China, were screened to estimate the emission rates of isoprene and monoterpenes by adopting bag-enclosure and curette sampling methods followed by a GC-FID analysis. It was found that the Ficus species were mainly emitting isoprene and most tropical vegetations were mainly releasing monoterpenes. The results also showed that the emissions of isoprene were affected by both temperature and PAR(Photosynthetic Active Radiation), while monoterpene emissions were mainly temperature-dependent.
View Article and Find Full Text PDFGuang Pu Xue Yu Guang Pu Fen Xi
July 2004
The gas-phase reaction of a-pinene with ozone was tailed by LP-FTIR under 1.0 x 10(5) Pa and (296 +/- 3)K. The spectra were analyzed and a preliminary predication of the possible products was made.
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