52 research outputs found

    Theory and simulation of colloids near interfaces: quantitative mapping of interaction potentials

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    The behavior of dense colloidal fluids near surfaces can now be probed in great detail with experimental techniques like video and confocal microscopy. In fact we are approaching a point where quantitative comparisons of experiments with particle-level theory, such as classical density functional theory (DFT), are appropriate. In a forward sense, we may use a known surface potential to predict a particle density distribution function from DFT; in an inverse sense, we may use an experimentally measured particle density distribution function to predict the underlying surface potential from DFT. In this dissertation, we tested the ability of the closure-based DFT to perform forward and inverse calculations on potential models commonly employed for colloidal particles and surface under different surface topographies. To reduce sources of uncertainty in this initial study, Monte Carlo simulation results played the role of experimental data. The accuracy of the predictions depended on the bulk particle density, potential well depth and the choice of DFT closure relationships. For a reasonable range of choices of the density, temperature, potential parameters, and surface features, the inversion procedure yielded particle-surface potentials to an accuracy on the order of 0.1 kBT. Our results demonstrated that DFT is a valuable numerical tool for microcopy experiments to image three-dimensional surface energetic landscape accurately and rapidly.

    Characterization of explosion propagation of coal dust deposited by gas explosion convolutions in closed pipelines

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    To explore the propagation characteristics of gas explosion-induced coal dust detonations in enclosed pipelines, a custom-developed experimental system was employed for gas explosions involving accumulated coal dust. Various aspects were focused such as explosion pressure, flame dynamics, and the interplay between pressure and flame in the context of different gas and coal dust concentrations. Additionally, Fluent Numerical simulation software was utilized for analyzing the dispersion behavior of coal dust. The results reveal that the peak explosion pressure inside the closed pipeline is the highest at a 10% gas concentration, surpassing the maximum pressures observed at 12% and 8% concentrations. At a gas concentration of 10% and coal dust mass concentration of 250 g/m3, the explosion pressure exhibits a unique pattern: initially increasing, then decreasing, and subsequently rising again in the gas phase, followed by a continuous ascent in the coal dust phase. As the coal dust concentration increases, this pattern remains evident, with a persistent upward trend in the coal dust section. Conversely, at 8% and 12% gas concentrations, the maximum explosion pressure consistently rises with increasing coal dust concentrations, but shows a declining trend at 10% gas concentration. Furthermore, the time taken for the flame front to traverse the pipeline is positively correlated with the distance traveled. The flame front reaches various checkpoints more rapidly at a 10% gas concentration than at 12% and 8%. The flame’s propagation speed first increases and then decreases over distance, reaching its fastest at 10% gas concentration. The explosion pressure-time curve during a gas explosion in a closed pipeline showcases two peak values. The initial peak is caused by the shock wave preceding the gas explosion. As the flame advances into the coal dust section, the pressure concurrently begins to rise, reaching its second peak as it synchronizes with the flame’s peak. Following the flame signal’s disappearance, the pressure gradually diminishes until the reaction ceases. In the enclosed pipeline, the precursor shock waves and reflected waves contribute to the dispersion of coal dust, forming a “vortex-like” dust cloud. This formation enhances the interaction between the coal dust and the deflagration wave. When the coal dust concentration is fixed, the degree of dispersion at 10% gas concentration is more effective than at 12% or 8%. Furthermore, at a constant gas concentration, the dispersion degree of coal dust decreases as its mass concentration increases

    Anti-cancer natural products isolated from chinese medicinal herbs

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    In recent years, a number of natural products isolated from Chinese herbs have been found to inhibit proliferation, induce apoptosis, suppress angiogenesis, retard metastasis and enhance chemotherapy, exhibiting anti-cancer potential both in vitro and in vivo. This article summarizes recent advances in in vitro and in vivo research on the anti-cancer effects and related mechanisms of some promising natural products. These natural products are also reviewed for their therapeutic potentials, including flavonoids (gambogic acid, curcumin, wogonin and silibinin), alkaloids (berberine), terpenes (artemisinin, β-elemene, oridonin, triptolide, and ursolic acid), quinones (shikonin and emodin) and saponins (ginsenoside Rg3), which are isolated from Chinese medicinal herbs. In particular, the discovery of the new use of artemisinin derivatives as excellent anti-cancer drugs is also reviewed

    Linear brain measurement: a new screening method for cognitive impairment in elderly patients with cerebral small vessel disease

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    BackgroundThe old adults have high incidence of cognitive impairment, especially in patients with cerebral small vessel disease (CSVD). Cognitive impairment is not easy to be detected in such populations. We aimed to develop clinical prediction models for different degrees of cognitive impairments in elderly CSVD patients based on conventional imaging and clinical data to determine the better indicators for assessing cognitive function in the CSVD elderly.Methods210 CSVD patients were screened out by the evaluation of Magnetic Resonance Imaging (MRI). Then, participants were divided into the following three groups according to the cognitive assessment results: control, mild cognitive impairment (MCI), and dementia groups. Clinical data were collected from all patients, including demographic data, biochemical indicators, carotid ultrasound, transcranial Doppler (TCD) indicators, and linear measurement parameters based on MRI.ResultsOur results showed that the brain atrophy and vascular lesions developed progressive worsening with increased degree of cognitive impairment. Crouse score and Interuncal distance/Bitemporal distance (IUD/BTD) were independent risk factors for MCI in CSVD patients, and independent risk factors for dementia in CSVD were Crouse Score, the pulsatility index of the middle cerebral artery (MCAPI), IUD/BTD, and Sylvian fissure ratio (SFR). Overall, the parameters with high performance were the IUD/BTD (OR 2.28; 95% CI 1.26–4.10) and SFR (OR 3.28; 95% CI 1.54–6.91), and the AUC (area under the curve) in distinguishing between CSVD older adults with MCI and with dementia was 0.675 and 0.724, respectively. Linear brain measurement parameters had larger observed effect than other indexes to identify cognitive impairments in CSVD patients.ConclusionThis study shows that IUD/BTD and SFR are good predictors of cognitive impairments in CSVD elderly. Linear brain measurement showed a good predictive power for identifying MCI and dementia in elderly subjects with CSVD. Linear brain measurement could be a more suitable and novel method for screening cognitive impairment in aged CSVD patients in primary healthcare facilities, and worth further promotion among the rural population

    A highly effective ferritin-based divalent nanoparticle vaccine shields Syrian hamsters against lethal Nipah virus

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    The Nipah virus (NiV), a highly deadly bat-borne paramyxovirus, poses a substantial threat due to recurrent outbreaks in specific regions, causing severe respiratory and neurological diseases with high morbidity. Two distinct strains, NiV-Malaysia (NiV-M) and NiV-Bangladesh (NiV-B), contribute to outbreaks in different geographical areas. Currently, there are no commercially licensed vaccines or drugs available for prevention or treatment. In response to this urgent need for protection against NiV and related henipaviruses infections, we developed a novel homotypic virus-like nanoparticle (VLP) vaccine co-displaying NiV attachment glycoproteins (G) from both strains, utilizing the self-assembling properties of ferritin protein. In comparison to the NiV G subunit vaccine, our nanoparticle vaccine elicited significantly higher levels of neutralizing antibodies and provided complete protection against a lethal challenge with NiV infection in Syrian hamsters. Remarkably, the nanoparticle vaccine stimulated the production of antibodies that exhibited superior cross-reactivity to homologous or heterologous henipavirus. These findings underscore the potential utility of ferritin-based nanoparticle vaccines in providing both broad-spectrum and long-term protection against NiV and emerging zoonotic henipaviruses challenges

    A Study on the Gains and Losses of the Ecosystem Service Value of the Land Consolidation Projects of Different Properties in Hubei Province: An Empirical Comparison Based on Plains, Mountains and Hills

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    In view of the differences of land use structure and ecological environment changes caused by land consolidation projects with different features and landforms, this paper uses the modified ecosystem service value estimation model to quantitatively evaluate the change patterns of the ecosystem service value (ESV) of land consolidation, development and arrangement projects in Hubei Province under plains, hills and mountains to provide a theoretical basis for the ecological transformation of land consolidation. The results show that, compared with the pre-land consolidation period, (1) the total amount of ESV in the land consolidation project areas has increased, whereas the land development and arrangement project areas have decreased. Under the same nature, the growth rate of land consolidation project areas is as follows: hills < plains < mountains, and the loss rate of land development and arrangement project areas are as follows: mountains > plains > hills and hills > mountains > plains, respectively. Under the same landform, the total loss rate of ESV in land development project areas is slightly lower than that in land arrangement project areas. (2) The total amount of ESV in the land consolidation project areas under different natures and landforms of the supply service function shows a decreasing trend, and the total amount of ESV of the adjustment service, support service and cultural service function shows an increasing trend in the land consolidation project areas, whereas the land development and arrangement project areas show a decreasing trend. There is an obvious value transformation process of “ecology for production” in the land development and arrangement areas

    A Study on the Gains and Losses of the Ecosystem Service Value of the Land Consolidation Projects of Different Properties in Hubei Province: An Empirical Comparison Based on Plains, Mountains and Hills

    No full text
    In view of the differences of land use structure and ecological environment changes caused by land consolidation projects with different features and landforms, this paper uses the modified ecosystem service value estimation model to quantitatively evaluate the change patterns of the ecosystem service value (ESV) of land consolidation, development and arrangement projects in Hubei Province under plains, hills and mountains to provide a theoretical basis for the ecological transformation of land consolidation. The results show that, compared with the pre-land consolidation period, (1) the total amount of ESV in the land consolidation project areas has increased, whereas the land development and arrangement project areas have decreased. Under the same nature, the growth rate of land consolidation project areas is as follows: hills plains > hills and hills > mountains > plains, respectively. Under the same landform, the total loss rate of ESV in land development project areas is slightly lower than that in land arrangement project areas. (2) The total amount of ESV in the land consolidation project areas under different natures and landforms of the supply service function shows a decreasing trend, and the total amount of ESV of the adjustment service, support service and cultural service function shows an increasing trend in the land consolidation project areas, whereas the land development and arrangement project areas show a decreasing trend. There is an obvious value transformation process of “ecology for production” in the land development and arrangement areas

    Therapeutic Potential of Pien-Tze-Huang: A Review on Its Chemical Composition, Pharmacology, and Clinical Application

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    Pien-Tze-Huang (PTH) is a famous and commonly used traditional Chinese medicine formula in China. It was first formulated by a royal physician of the Ming Dynasty (around 1555 AD). Recently, PTH has attracted attention worldwide due to its beneficial effects against various diseases, especially cancer. This paper systematically reviewed the up-to-date information on its chemical composition, pharmacology, and clinical application. A range of chemical compounds, mainly ginsenosides and bile acids, have been identified and quantified from PTH. Pharmacological studies indicated that PTH has beneficial effects against various cancers, hepatopathy, and ischemic stroke. Furthermore, PTH has been used clinically to treat various diseases in China, such as colorectal cancer, liver cancer, and hepatitis. In summary, PTH is a potential agent with extensive therapeutic effects for the treatment of various diseases. However, the lack of information on the side effects and toxicity of PTH is a non-negligible issue, which needs to be seriously studied in the future
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