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Morphine infusion through Intrathecal Drug Delivery System (IDDS) is widely used to relieve refractory cancer pain. However, continuous escalation of morphine dose caused by opioid tolerance and/or progress of cancer was commonly observed. Combining morphine with medications of different analgesic mechanisms is applied to blunt the rate of morphine increase. The purpose of this study was to determine the analgesic efficacy and safety of combining gabapentin with morphine after IDDS implantation. This study compared patients that received IDDS implantation from January 1, 2017 to November 10, 2018 in our institute. Key outcomes included change in mean pain score, dose of morphine used in patients, percentage of patients with 30% and 50% reduction in mean pain score, Patient Global Impression of Change scores, breakthrough pain characters and side effects. 34 patients in the combination group (morphine + gabapentin) and 40 patients in the monotherapy group(morphine)were analyzed. The results showed that both therapy groups achieved similar analgesic efficacy, demonstrated by Numerical rating scale (2.42 ± 0.88 vs 2.57 ± 0.85; Combination vs Monotherapy), PGIC and responder status. Mean daily dose of morphine was significantly lower in combination group compared to monotherapy group (3.54 ± 1.29 mg vs 4.64 ± 1.28 mg, P = 0.007). More patients experienced dizziness and somnolence after receiving combination therapy compared to morphine-alone treatment although no statistical significance was found (P = 0.49). Addition of gabapentin achieved similar analgesic efficacy with lower dose of morphine compared to morphine alone accompanying with higher incidence of dizziness and somnolence.

Experiments were carried out to study the dynamic and thermal characteristics of rockslide motion using a model slope with sliding blocks of varying parameters. A high-speed camera for block velocity, an acceleration acquisition system for impact acceleration, and a thermal infrared camera for heating. The results between the recorded velocities and theoretical are consistent for sliding blocks. The impact acceleration shows complex non-stationary characteristics over a very short time duration (~ 0.01 s), high amplitude (up to 5 g measured near the impact point), high-frequency motion (generally 100–300 Hz), and rapid attenuation. The thermal infrared images show that impact heating is substantially higher than frictional heating. The thermal analysis indicates frictional heating of 1–4.6 °C, whereas impact heating reached 20–60 °C. The temperatures during sliding were affected by the velocity, contact stiffness, and mass of the sliding block, with velocity showing the strongest influence. The impact heat dissipated very rapidly: 80% dissipated within 2 s, 95% within 5 s, and 98% within 10 s. The results of this study can be used as a future reference, and the impact characteristics provide guidelines for the development of disaster prevention measures. Moreover, the high temperatures verified in the tests provide meaningful information for studies on the sliding surface and movement speed of landslides.

International food trade poses food safety risks through the collateral transport of contaminants that are harmful to human health. Persistent organic pollutants, such as the polychlorinated biphenyl (PCB) congener PCB-153, are consumed via fish intake traded globally, but the estimated daily intake and risk to human health are poorly understood. Using a food trade pathway model, a global-scale atmospheric persistent organic pollutant transport model and UN Global Comtrade data, high PCB exposure was identified in Western Europe. Marine fish exported from Europe to Sub-Saharan African countries account for 84% of PCB-153 consumer exposure. In contrast, European fish consumers face reduced exposure to PCB-153 by consuming marine fish imported from countries where PCB-153 concentrations are low. People consuming aquaculture-farmed salmon fed with marine ingredients from PCB-153-contaminated seawaters face a higher PCB exposure. Our findings demonstrate that global fish trade can exacerbate PCB-153 exposure in regions where environmental PCB-153 levels are low. This approach demonstrates how the exposure to harmful food contaminants distributed through global food trade can be predicted and quantified. Food safety is jeopardized by the global trade in contaminated foods. Huang et al. demonstrate how consumer exposure to the toxic chemical polychlorinated biphenyl-153 (PCB-153) can be modelled and identify regions with high consumer PCB-153 exposure resulting from imported fish consumption.

ObjectivesThis study evaluated the analgesic efficacy and safety of CT-guided iodine-125 (125I) brachytherapy in patients with spinal metastasis-induced pain who were not suitable to receive radiotherapy.MethodsA cohort of 68 patients with spinal metastasis induced pain not fully relieved by opioids and did not receive external beam radiation therapy due to poor general status were enrolled and underwent CT-guided 125I brachytherapy for analgesic treatment.ResultsPatients were followed for 8 weeks after brachytherapy. Mean Numerical Rating Scale score before brachytherapy was 7.3±1.3 and decreased to 3.3±0.9, 2.6±0.8, 2.7±0.8, 2.9±0.9 and 3.3±1.1 at weeks 1, 2, 4, 6 and 8, respectively, after brachytherapy. Daily dose of morphine equivalent was 105.1±28.0 mg before brachytherapy and decreased to 45.3±13.7, 39.9±14.2, 40.4±14.9, 48.5±18.0 and 62.4±17.5 mg at weeks 1, 2, 4, 6 and 8, respectively, after brachytherapy. Patients had fewer daily episodes of breakthrough pain after brachytherapy (pConclusionsCT-guided 125I brachytherapy is an effective and safe intervention for patients with spinal metastasis-induced pain who are not able to receive radiation therapy.

The bioaccumulation and adverse effects of organophosphorus flame retardants (OPFRs) on human health have become a global concern. China produces the largest amount of OPFRs globally and has the highest global market share. However, little is known about its emission level and environmental cycling, thereby causing uncertainties in the assessment of the environmental and health impacts of OPFRs. We developed a gridded annual OPFRs emission inventory at 1/4° longitude by 1/4° latitude resolution over China from 2014 to 2018. The results show that the annual OPFRs emissions increased from approximately 670 tons/yr in 2014 to 1000 tons/yr in 2018 in China. Higher OPFR emissions were identified in Jiangxi, Shandong, Beijing-Tianjin-Hebei (BTH), Yangtze River Delta (YRD), and Pearl River Delta (PRD). In total, 2400 tons of OPFRs were released into the atmosphere during the multi-year period, in which production accounting for 56.6% of total OPFR emissions in China. An atmospheric transport model, the Canadian Model for Environmental Transport of Organochlorine Pesticides (CanMETOP), was employed to verify the gridded emission inventory and elucidate the atmospheric environmental fate of OPFRs. Modeled OPFRs in the air and soil agreed reasonably well with observed data, suggesting that the developed inventory was, to a large extent, reliable. The modeled atmospheric and surface soil concentrations of OPFRs across China ranged from 0 to 119 ng/m3 and 0 to 428 ng/g, respectively. East China is subjected to more intense OPFR contamination than the rest of the country. The results provide a valuable dataset and assessment of OPFRs, which may aid policy-makers and the scientific community in developing emission control strategies and evaluating the health and environmental consequences of OPFRs in China.

A probabilistic slope stability analysis framework based on the Newmark permanent displacement method and probability density evolution theory is presented to quantify the coupling impact a...

In this study, we collected 308 serum samples from 17 to 20 year old first-year university students who were recruited from Lanzhou University in China a few days after their enrollment to measure the serum Pb, Cd, Hg, and As levels, and specific questionnaires for age, sex, settlement and dietary structure were designed. A 3-D atmospheric transport model was used to simulate the atmospheric concentration and dry deposition across China based on gridded Pb emission inventory to examine the association between the spatial distribution of serum concentrations and environmental fates of Pb. The mean serum Pb, Cd, Hg, and As concentrations averaged over all participating young students were 21.38, 1.46, 3.86, and 4.69 μg/L, respectively. The Pb, Cd, and Hg levels in 3%, 7%, and 20% serum samples exceeded the standards. The minimum serum As and Hg concentrations and the maximum serum Pb and Cd concentrations occurred in urban areas. Seafood diet habits (P 0.05), sex (P 0.05), and relocation (P 0.01) caused significant differences in serum As, Pb, and Cd concentrations. A cluster analysis was carried out to classify the exposure pathways for target contaminants. The results indicated that 4 heavy metals in the serum of volunteers from northern China could be grouped into the same category, in which significant positive correlations were found between the serum heavy metal levels and background concentrations of surface soil. However, in other provinces and metropolises, the atmospheric pollution level played a critical role involving in the inhalation exposure pathway. We demonstrated that serum Pb levels in freshman students were related to the atmospheric transport and dry deposition of Pb.

The natural and artificial sand soils always incorporate other small particles, which makes the soil liquefaction resistance difficult to predict. The particle size may change from 10−5 m (e.g., fine particles) to 10−8 m (e.g., ultrafine particles), and the soil behaviors change dramatically when such particles are present. Newly reported soil liquefaction cases involving fine particles provide great challenges to seismic design codes. To make it clear, this paper reviewed effects of small particles on soil liquefaction in three different types. The non-low plastic fines (5–75 μm), clay particles (0.1–5 μm), and ultrafine particles (1–100 nm) are discussed, respectively. Many scholars found that liquefaction resistance decreased at first but increased as fine particles (non-low plastic fines or clay particles) were added. This phenomenon can be attributed to the lubrication effect of fine particles. However, when particles in nanometer scale, the strong bond between particles and hydration adsorption of nano-suspension improve liquefaction resistance. There are still many challenges to understanding the roles of small particles in liquefaction, for example, determining relative density for a high fine content, determining particle shape effect (e.g., aspect ratio, flatness, and particle roundness), as well as the long-term reinforcement performance of ultrafine particles. In engineering practice, it suggests that the seismic design codes address the effects of non-plastic fines in laboratory tests. As for some new liquefaction mitigation methods by ultrafine particles, we believe that the standard penetration test may not be appropriate to evaluate soil improvement effect, because the test results cannot reflect the properties change of pore water.

An anchored pile structure is a type of retaining structure that is widely used in excavation support systems, water-front structures, slope stabilization, and landslide prevention. This structure has good performance because the anchor can limit the displacement and control the deflection of the pile head. Field observations of the performance of various retaining structures during many recent earthquakes have revealed that these structures behave particularly well. However, the dynamic responses and seismic performance of this type of retaining structure in slope stabilization have not been elucidated. In this study, a large-scale shaking table test was conducted to investigate the seismic behavior of a landslide reinforced by anchored pile structures. The acceleration field, anchor force, bending moment, lateral earth pressure along the pile, and permanent displacement of the slope and pile are presented and discussed to systematically determine the seismic responses, reinforcement, and failure mechanism of this retaining structure. The tests results reveal that a landslide reinforced by anchored pile structures achieved good seismic performance even under strong earthquakes. Additionally, some reasonable measures are proposed to improve the seismic performance of a slope reinforced by anchored pile structures. The results obtained by this study can provide a theoretical basis for the seismic performance assessment and design of anchored pile structures.

Earthquake-induced landslides have resulted in huge casualties and considerable financial repercussions, and slope dynamic response analysis has always been a hot issue. The prediction of the dynamic response of a slope before the occurrence of future earthquakes will benefit disaster prevention and reduction. Traditional methods (such as the finite element method) are mostly based on simplified physical mechanisms and cannot accurately predict the dynamic response of complicated slope systems. This article innovatively applies novel recurrent neural networks to the prediction of the slope dynamic response. Using the results of large-scale shaking-table tests, we introduced a moving-steps strategy and established three recurrent neural network models: Simple-RNN, LSTM and GRU models. Moreover, a multi-layer perceptron prediction model was trained for comparative verification. We also conducted three experiments to investigate the effect of the data volume on the models. Results show that recurrent neural networks perform well in the analysis of the seismic dynamic response of a slope and provide better predictions than the multi-layer perceptron network. When there are many data, the LSTM and GRU models have advantages, and the confidence indexes of their predictions with normalized error within ±5% are 84.5% and 86.4%, respectively. It is concluded that recurrent neural networks are suitable for the time-series prediction of dynamic responses to seismic loads. To some extent, this paper may help reduce the future risks and losses of earthquake-triggered landslide disasters.

Polycyclic aromatic hydrocarbons (PAHs) are omnipresent air pollutants with mutagenic and carcinogenic characteristics. Lanzhou city in Northwest China, where the first photochemical smog incident occurred in China, is located in an area characterized by mountain-valley topography. The city has been known as a heavy and petrochemical industry base and heavily contaminated by PAHs. There are large knowledge gaps in the understanding of atmospheric environmental fate of PAHs in Lanzhou city due to sparse observation data. We performed extensive numerical investigations of PAHs for August (summertime) and December (wintertime) of 2014 in Lanzhou city, using the Community Multiscale Air Quality (CMAQ) model, aiming to fill knowledge gaps in the spatial-temporal distribution and health consequences across the city. Strong seasonality in the atmospheric concentrations of PAHs was found, with high concentrations in winter and low concentrations in summer. The modeling results show high days in which daily air concentrations of BaP exceeding the level Ⅱ of Chinese National Standard (CNS) (2.5 ng/m3) in several August days in industrial suburb and urban area. In December, 77% and 80% of simulated BaP daily air concentrations were well above this national standard in the two areas. The modeled NAP and PHE in the atmosphere were predominantly in gas phase, whereas BaP was mainly in particulate phase. It was also found that the dry deposition dominated total PAHs deposition in Lanzhou. The incremental lifetime cancer risk (ILCR) ranged from 4.0 × 10−6 to 16.0 × 10−6, which were higher than the satisfactory risk level of 1.0 × 10−6, suggesting that local residents in Lanzhou city have a potential carcinogenic risk through exposure to ambient BaP. Especially, children had a higher exposure risk than adults. We suggest that the different actions in different regions of the city should be taken by the local government and those industries with high PAH emission, so as to reduce PAH contamination and risk.

Slopes should be regarded as stochastic dynamic systems when investigating the uncertainty of ground motions. In engineering, this involves the propagation and spatial evolution of physical quantities (e.g., acceleration) that can be assessed with some probability. More specifically, stochastic stability and amplification effects are important issues under random seismic inputs. In studying the above, a large-scale shaking-table test is carried out to investigate the slope seismic response under random earthquake ground motions, where 144 ground-motion samples are generated using a time-evolution power spectrum model. In this test, acceleration evolves in a way that its PDF changes with time and space. In the time domain, the PDF variability first increases and then decreases with the progression of the earthquake. In the spatial domain, the PDF variability increases upslope, indicating that the mean and standard deviation of amplification factors increase with elevation. Moreover, the stability of the upper part of the slope stochastic dynamic system is poor. Meanwhile, the de-amplification effect of the slope toe is identified under random seismic inputs. Finally, we discuss different amplification factors and consider applications of the research results in slope engineering.

As the largest petrochemical industrialized city in northwestern China since the 1950s, Lanzhou has been well-known for its heavy surface ozone pollution. Given abundant emission sources of ozone precursors and the favorable environmental conditions for O3 formation, this study performed extensive atmospheric chemistry modeling investigations subject to 11 emission control scenarios. These scenarios increased and decreased emission levels of total volatile organic compound (TVOC) and nitrogen oxides (NOx), the two surface ozone (O3) precursor gases, to examine the relationships between O3 and NOx and TVOC. The modeling investigation was carried out for the summer of 2016 in the downtown and petrochemical industrial suburb in the city of Lanzhou. The results revealed that surface O3 in the downtown area of Lanzhou was controlled by VOCs and in the petrochemical-industrialized western suburb by NOx. Higher ozone levels were simulated in the west suburb of the city as compared with the downtown area, agreeing with measured data. The relationships between modeled TVOC/NOx ratios and O3 reductions, as well as the titration effect, were also discussed. The model results provided useful references for the mitigation strategy of ozone reduction in Lanzhou and other major cities in northwest China with similar climate and topography conditions.

Finding the critical slip surface and estimating the landslide volume are of primary importance for slope seismic design. However, this may be difficult due to the uncertainty of ground motions. To address this problem, a new method for calculating uncertainties is recommended in this paper, especially for the critical slip surface and landslide volume under random earthquake ground motions. Firstly, a series of intensity–frequency nonstationary random earthquake ground motions were generated based on an improved orthogonal expansion method. A given number of potential slip surfaces were set in a soil slope. Subsequently, the factor of safety (FOS) of each slip surface for all ground motions was calculated and the minimum FOS curves were obtained. It was found that the critical slip surfaces and failure times are uncertain under different earthquakes. The Monte Carlo method was used to verify the accuracy of probability density evolution method (PDEM), and the results of the PDEM and the Monte Carlo method are consistent, meaning that the PEDM has higher computational efficiency. Moreover, the distributions of earthquake-triggered landslide volume and landslide depth were analyzed by considering equivalent extreme events. Both landslide volume and depth exhibit a normal distribution for a homogeneous soil slope. The framework of this study is meaningful for slope seismic design in engineering, for example, the location of critical slip surface can be used for slope reinforcement, and the distribution of sliding volume can be used for disaster assessment.