There are widespread concerns about urban sprawl in China. In response, modeling and assessing urban expansion and subsequent land use and land cover (LULC) changes have become important approaches ...to support decisions about appropriate development and land resource use. Guangzhou, a major metropolitan city in South China, has experienced rapid urbanization and great economic growth in the past few decades. This study applied a series of Landsat images to assess the urban expansion and subsequent LULC changes over 35 years, from 1979 to 2013. From start to end, urban expansion increased by 1512.24 km² with an annual growth rate of 11.25 %. There were four stages of urban growth: low rates from 1979 to 1990, increased rates from 1990 to 2001, high rates from 2001 to 2009, and steady increased rates from 2009 to 2013. There were also three different urban growth types in these different stages: edge-expansion growth, infilling growth, and spontaneous growth. Other land cover, such as cropland, forest, and mosaics of cropland and natural vegetation, were severely impacted as a result. To analyze these changes, we used landscape metrics to characterize the changes in the spatial patterns across the Guangzhou landscape and the impacts of urban growth on other types of land cover. The significant changes in LULC and urban expansion were highly correlated with economic development, population growth, technical progress, policy elements, and other similar indexes.
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CEKLJ, EMUNI, FIS, FZAB, GEOZS, GIS, IJS, IMTLJ, KILJ, KISLJ, MFDPS, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, SBMB, SBNM, UKNU, UL, UM, UPUK, VKSCE, ZAGLJ
•Meadow patch coverage (MPC) regulated runoff and sediment under natural rainfall.•MPC had a greater impact on sediment yield than runoff volume in alpine area.•The greater MPC, the greater runoff ...coefficient and the lower sediment concentration.•Maintaining runoff is crucial to water conservation capacity of alpine meadow.
Soil and water conservation is the most important among ecological functions of alpine meadow on the Qinghai-Tibetan Plateau. Quantitative assessment of the effects of meadow patch coverage (MPC) on the runoff and sediment processes in alpine meadow is urgent for predicting the water conservation function of this special alpine ecosystem. Here, a field experiment was conducted to determine the effects of different meadow patch coverage through runoff and sediment processes in a typical alpine meadow on the eastern Qinghai-Tibetan Plateau. The results showed that runoff in 30% and 60% MPC plots were 39.4% and 37.9% less than in 90% MPC plot, respectively. The sediment yield in 60% and 90% MPC plots were 77.9% and 82.1% less than in 30% MPC plot, respectively. The sediment concentration in 30% MPC in heavy rainfall scenario is 4.34 times and 6.51 times higher than that in light rainfall scenario and moderate rainfall scenario, respectively. Our results indicated that MPC presented a greater impact on sediment yield than runoff volume, although runoff was greatly affected by rainfall. The higher MPC followed the greater runoff coefficient and the lower sediment concentration. The influences of MPC on runoff and sediment yield in light rainfall scenario and moderate rainfall scenario were weaker than those in heavy rainfall scenario. It is necessary to maintain surface runoff while controlling soil loss for realizing the sustainability of alpine meadow ecosystems. Therefore, these findings may conducive to offer a theoretical guidance to achieve the combined goal of soil erosion regulation during alpine meadow degradation on the Qinghai-Tibetan Plateau.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
The development of an economic, environmental-friendly and energy-saving process for the selective depolymerization of lignin is an outstanding challenge. Herein, a novel and efficient ...visible-light-induced photocatalytic process for the selective depolymerization of lignin model compounds and organosolv lignin was first developed by using perylene diimide (PDI) as a metal-free organocatalyst. Interestingly, it can completely decompose the oxidized lignin models to phenolic and ketone fragmentation molecules with very high selectivity at room temperature under visible light illumination. Furthermore, the use of a home-made photocatalytic continuous-flow reactor efficiently shortened the reaction time within an hour. Even for organosolv lignin, nearly 86% mass ratio of lignin was degraded to low-molecular-mass monoaromatic or diaromatic products. We found that superior performances were realized by single-electron transfer (SET) from the photoexcited strongly reducing PDI&z.rad;
−
anion to the ketone groups of the β-O-4 linkage in the lignin.
A novel and efficient strategy for the selective depolymerization of lignin model compounds and organosolv lignin
via
a visible-light-induced photocatalytic continuous-flow reactor was first developed by using perylene diimide (PDI) as a organocatalyst.
Expressions are derived for calculating the three-dimensional acoustic radiation force (ARF) on a multilayer microsphere positioned arbitrarily in a Gaussian beam. A theoretical model of a ...three-layer microsphere with a cell membrane, cytoplasm, and nucleus is established to study how particle geometry and position affect the three-dimensional ARF, and its results agree well with finite-element numerical results. The microsphere can be moved relative to the beam axis by changing its structure and position in the beam, and the axial ARF increases with increasing outer-shell thickness and core size. This study offers a theoretical foundation for selecting suitable parameters for manipulating a three-layer microsphere in a Gaussian beam.
High-performance flexible pressure sensors have great application prospects in numerous fields, including the robot skin, intelligent prosthetic hands and wearable devices. In the present study, a ...novel type of flexible piezoresistive sensor is presented. The proposed sensor has remarkable superiorities, including high sensitivity, high repeatability, a simple manufacturing procedure and low initial cost. In this sensor, multi-walled carbon nanotubes were assembled onto a polydimethylsiloxane film with a pyramidal microarray structure through a layer-by-layer self-assembly system. It was found that when the applied external pressure deformed the pyramid microarray structure on the surface of the polydimethylsiloxane film, the resistance of the sensor varied linearly as the pressure changed. Tests that were performed on sensor samples with different self-assembled layers showed that the pressure sensitivity of the sensor could reach - 2.65 kPa - 1 , which ensured the high dynamic response ability and the high stability of the sensor. Moreover, it was proven that the sensor could be applied as a strain sensor under the tensile force to reflect the stretching extent or the bending object. Finally, a flexible pressure sensor was installed on five fingers and the back of the middle finger of a glove. The obtained results from grabbing different weights and different shapes of objects showed that the flexible pressure sensor not only reflected the change in the finger tactility during the grasping process, but also reflected the bending degree of fingers, which had a significant practical prospect.
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IZUM, KILJ, NUK, PILJ, PNG, SAZU, UL, UM, UPUK
The preferred agent of glucocorticoids in the treatment of patients with severe COVID-19 is still controversial. This study aimed to compare the efficacy and safety of methylprednisolone and ...dexamethasone in the treatment of patients with severe COVID-19.
By searching the electronic literature database including PubMed, Cochrane Central Register of Controlled Trials, and Web of Science, the clinical studies comparing methylprednisolone and dexamethasone in the treatment of severe COVID-19 were selected according to the inclusion criteria and exclusion criteria. Relevant data were extracted and literature quality was assessed. The primary outcome was short-term mortality. The secondary outcomes were the rates of ICU admission and mechanical ventilation, PaO
/FiO
ratio, plasma levels of C-reactive protein (CRP), ferritin, and neutrophil/lymphocyte ratio, hospital stay, and the incidence of severe adverse events. Statistical pooling applied the fixed or random effects model and reported as risk ratio (RR) or mean difference (MD) with the corresponding 95% confidence interval (CI). Meta-analysis was performed using Review Manager 5.1.0.
Twelve clinical studies were eligible, including three randomized controlled trials (RCTs) and nine non-RCTs. A total of 2506 patients with COVID-19 were analyzed, of which 1242 (49.6%) received methylprednisolone and 1264 (50.4%) received dexamethasone treatment. In general, the heterogeneity across studies was significant, and the equivalent doses of methylprednisolone were higher than that of dexamethasone. Our meta-analysis showed that methylprednisolone treatment in severe COVID-19 patients was related to significantly reduced plasma ferritin and neutrophil/lymphocyte ratio compared with dexamethasone, and that no significant difference in other clinical outcomes between the two groups was found. However, subgroup analyses of RCTs demonstrated that methylprednisolone treatment was associated with reduced short-term mortality, and decreased CRP level compared with dexamethasone. Moreover, subgroup analyses observed that severe COVID-19 patients treated with a moderate dose (2 mg/kg/day) of methylprednisolone were related to a better prognosis than those treated with dexamethasone.
This study showed that compared with dexamethasone, methylprednisolone could reduce the systemic inflammatory response in severe COVID-19, and its effect was equivalent to that of dexamethasone on other clinical outcomes. It should be noted that the equivalent dose of methylprednisolone used was higher. Based on the evidence of subgroup analyses of RCTs, methylprednisolone, preferably at a moderate dose, has an advantage over dexamethasone in the treatment of patients with severe COVID-19.
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DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Purpose. Tumor immunity serves an essential role in the occurrence and development of thyroid cancer (THCA). The aim of this study is to establish an immune-related prognostic model for THCA patients ...by using immune-related genes (IRGs). Methods. Wilcox test was used to screen the differentially expressed immune-related genes (DEIRGs) in THCA and normal tissues, then the DEIRGs related to prognosis were identified using univariate Cox regression analysis. According to The Cancer Genome Atlas (TCGA) cohort, we developed a least absolute shrinkage and selection operator (LASSO) regression prognostic model and performed validation analyses regard to the predictive value of the model in internal (TCGA) and external (International Cancer Genome Consortium) cohorts respectively. Finally, we analyzed the correlation among the prognostic model, clinical variables, and immune cell infiltration. Results. Eighty-two of 2,498 IRGs were differentially expressed between THCA and normal tissues, and 18 of them were related to prognosis. LASSO Cox regression analysis identified seven DEIRGs with the greatest prognostic value to construct the prognostic model. The risk model showed high predictive value for the survival of THCA in two independent cohorts. The risk score according to the risk model was positively associated with poor survival and the infiltration levels of immune cells, it can evaluate the prognosis of THCA patients independent of any other clinicopathologic feature. The prognostic value and genetic alternations of seven risk genes were evaluated separately. Conclusion. Our study established and verified a dependable prognostic model associated with immune for THCA, both the identified IRGs and immune-related risk model were clinically significant, which is conducive to promoting individualized immunotherapy against THCA.
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DOBA, FZAB, GIS, IJS, IZUM, KILJ, NLZOH, NUK, OILJ, PILJ, PNG, SAZU, SBCE, SBMB, SIK, UILJ, UKNU, UL, UM, UPUK
•Hydrous thermo-simulation experiments on oil shale have been performed.•The formation mechanism of pyrolysates in the presence of water was evaluated.•The consecutive first order reaction model ...involving bitumen as an intermediate product was developed.•The kinetics parameters were calculated using experimental data.
The hydrous thermo-simulation experiments on oil shale sample from Liushuhe basin have been performed using autoclave. The mechanism and kinetics of oil shale pyrolysis were investigated. The formation mechanism of pyrolysates including retorting gas, oil and bitumen, were evaluated in the presence of saturated and unsaturated water, respectively. The results show that the physicochemical properties of water have greatly changed in high temperature and pressure. At the same time, water has three kinds of effect on the oil shale pyrolysis, including the protection of free radical, catalytic action and swelling. The pyrolysis temperature was carried out about 70 °C earlier, and the generated processing of hydrocarbon would be easier under the aqueous. The consecutive first order reaction model involving bitumen as an intermediate product was used in the data analysis in order to determine the pyrolysis kinetic parameters. It was found that the apparent activation energy of kerogen pyrolysis was lower than bitumen pyrolysis.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
In recent years, various convolutional neural network (CNN) based frameworks have been presented to detect forged regions in images. However, most of the existing models can not obtain satisfactory ...performance due to tampered areas with various sizes, especially for objects with large-scale. In order to obtain an accurate object-level forgery localization result, we propose a novel hybrid transformer architecture, which exhibits both advantages of spatial dependencies and contextual information from different scales, namely, TransU2-Net. Specifically, long-range semantic dependencies are captured by the last block of encoder to locate large-scale tampered areas more completely. Meanwhile, non-semantic features are filtered out by enhancing low-level features under the guidance of high-level semantic information in the skip connections to achieve more refined spatial recovery. Therefore, our hybrid model can locate spliced forgeries with various sizes without requiring large data set pre-training. Experimental results on the Casia2.0 and Columbia datasets show that our framework achieves better performance over state-of-the-art methods. On the Casia 2.0 dataset, F-measure improve by 8.4% compared to the previous method.
The fast developing international trade of products based on traditional knowledge and their value chains has become an important aspect of the ethnopharmacological debate. The structure and ...diversity of value chains and their impact on the phytochemical composition of herbal medicinal products, as well as the underlying government policies and regulations, have been overlooked in the debate about quality problems in transnational trade. Rhodiola species, including Rhodiola rosea L. and Rhodiola crenulata (Hook. f. & Thomson) H. Ohba, are used as traditional herbal medicines. Faced with resource depletion and environment destruction, R. rosea and R. crenulata are becoming endangered, making them more economically valuable to collectors and middlemen, and also increasing the risk of adulteration and low quality. Rhodiola products have been subject to adulteration and we recently assessed 39 commercial products for their composition and quality. However, the range of Rhodiola species potentially implicated has not been assessed. Also, the ability of selected analytical techniques in differentiating these species is not known yet. Using a strategy previously developed by our group, we compare the phytochemical differences among Rhodiola raw materials available on the market to provide a practical method for the identification of different Rhodiola species from Europe and Asia and the detection of potential adulterants. Nuclear magnetic resonance spectroscopy coupled with multivariate analysis software and high performance thin layer chromatography techniques were used to analyse the samples. Rosavin and rosarin were mainly present in R. rosea but also in Rosea sachalinensis Borris. 30% of the Rhodiola samples purchased from the Chinese market were adulterated by other Rhodiola spp. The utilization of a combined platform based on (1)H-NMR and HPTLC methods resulted in an integrated analysis of different Rhodiola species. We identified adulteration at the earliest stage of the value chains, i.e., during collection as a key problem involving several species. This project also highlights the need to further study the links between producers and consumers in national and trans-national trade.
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