Urban agglomeration has the function of being an incubator for innovation. Previous studies have only focused on the output of innovation, ignoring the knowledge cooperation and exchange between ...cities, which is an important embodiment of the incubation. Compared with scientific cooperation, technical cooperation is more experimental and application oriented, requires more face-to-face communication, and is more sensitive to distance. In this paper co-patent data were selected to show the development and differences of intercity technological cooperation networks within Chinese urban agglomerations. The results show that the technical cooperation network within Chinese urban regions has generally developed rapidly in the past decade, especially those in eastern China, which have become the closest urban regions in China's technical cooperation.
The unprecedented urbanization recently has inevitably intensified the changes in land use morphology. However, current studies on land use primarily analyze a single morphology, ignoring the ...relationships between different land use morphologies. Taking the northern slope of the Tianshan Mountains (NSTM) as the study area, this article quantifies the spatiotemporal pattern of land use change, and estimates trade-offs and synergies between dominant (patch density, largest patch index, and landscape shape index) and recessive (land use efficiency, land use intensity, and agricultural non-point source pollution) morphologies to fully understand the dynamic characteristics of land use. Results showed bare areas and grassland were always predominant land use types, and land use change from 1990 to 2020 was characterized by the increase of impervious surfaces and the decrease of bare areas. The strongest trade-off was found between largest patch index and land use intensity, while the synergy between landscape shape index and land use intensity was strongest. There are significant disparities in terms of temporal and spatial patterns of trade-offs/synergies. The correlation coefficients in different study periods were much smaller than their estimations in the whole region, and the trade-offs/synergies in the eastern NSTM were basically identical with the whole relationships. The findings reveal the interactions among various land use characteristics, and provide significant references for coordinated land management and regional high-quality development.
•Two interactive coupling models were developed on urbanization and eco-environment.•We find the double-exponential curve is in the form of an inverted-U curve.•The dynamic of coordination evolved ...into a superior balance in rapid urbanization.•The coordinated patterns of most sample cities are sensitive to the eco-environment.
China's high-speed economic growth has been characterized by rapid urbanization and a series of environmental issues. This study investigates the urbanization and eco-environment system from the perspective of interactive coercing theory and proposes a new comprehensive index system for the assessment of urbanization and the eco-environment. This is done using interactive coercing model (ICM) followed by a dynamic coupling coordination degree model (DCCDM) to estimate the relationship between urbanization and the eco-environment. This study focuses on the interactive coercing relationship, coupling coordination degree and coordinated patterns in the BTH (Beijing–Tianjin–Hebei) region, China, with panel data collected from 1980 to 2011. The main conclusions are as follows: (1) demographic urbanization and eco-environmental endowment make the greatest contribution to the compound system, indicating that they are the critical factors to consider when analyzing the interactive coercing relationship between urbanization and the eco-environment; (2) we find the double-exponential curve of urbanization and the eco-environment is in the form of an inverted-U curve, and thus the Kuznets hypothesis is confirmed by the empirical analysis; and (3) the dynamic of coordination of the selected cities shows an S-shaped curve and the corresponding state of the degrees evolves into the rudimentary symbiosis phase from the harmonious development phase during rapid urbanization, and it is revealed that the coordinated patterns of most sample cities are sensitive to the eco-environment, which indicates that the urban environment is subject to great pressure. The comprehensive indexes and the interactive coupling models may help the governments better understand the complex coupling relationship, and develop sustainable urbanization development strategies that better balance urbanization and eco-environmental protection.
•Compliance minimization under volume and buckling constraints is considered.•A new approach is developed for dealing with pseudo eigenvalue modes.•The eigenvalue shift and pseudo mode identification ...techniques are employed.•Two-phase optimization algorithms are developed.•Numerical results are presented to illustrate the effectiveness of the algorithms.
This paper presents a study on topology optimization of continuum structures under buckling constraints. New algorithms are developed for minimization of structural compliance considering constraints on volume and buckling load factors. The SIMP (Solid Isotropic Material with Penalization) material model is employed and nodal relative densities are used as topology design variables. A new approach based on the eigenvalue shift and pseudo mode identification is proposed for eliminating the effect of pseudo buckling modes. Two-phase optimization algorithms are also proposed for achieving better optimized designs. Numerical examples are presented to illustrate the effectiveness of the new methods.
China’s Belt and Road Initiative (BRI) presents the world with a new era of inclusive globalization, which will shape urbanization patterns globally. This study considered the launch of BRI as a ...quasi-experiment, where we evaluated the BRI’s impact on urbanization by way of difference-in-differences (DID) and propensity score matching (PSM) methods. The results showed that the BRI exerted a significantly negative effect on urbanization in its first three years. Its positive effect emerged from the fifth year onwards, indicating that the BRI’s positive effect on urbanization required a period of practical experience. Heterogeneous analysis and placebo test were also conducted to verify the robustness of the model. The effects in low-income countries were revealed to have been much greater than in high-income countries, meaning the BRI had been conducive to promote local urban growth in underdeveloped economies. Finally, the geographical detector model was introduced to discuss the influencing mechanism of urbanization in BRI and non-BRI countries, showing external factors were the prominent driving forces in BRI countries, whereas internal drivers played an important role in non-BRI countries. Our findings indicated that the implementation of the BRI contributed to building global economic growth and supporting a shared future.
Squamous cell lung cancer (SqCLC) is among the most malignant lung cancers worldwide, lacking biomarkers for diagnostic and targets for treatment. In this study, we observed that miR-140-3p was ...expressed at low levels both in SqCLC cell lines and patient samples, while overexpression of miR-140-3p dramatically reduced the cell proliferation and invasion in SqCLC cells and Patient derived xenograft (PDX) models. Our further investigation indicated miR-140-3p negatively affected the tumorigenesis of SqCLC by down-regulating the expression of BRD9, an oncogene in SqCLC. Inhibition of BRD9 repressed SqCLC tumorigenesis by regulating c-myc expression. Meanwhile, BRD9 expression is up-regulated and negatively correlated with miR-140-3p in clinical samples; a meta-analysis of survival data indicates that SqCLC patients with high levels of BRD9 in their tumors have a worse prognosis. Collectively, our study suggests the prognostic and therapeutic roles of miR-140-3p and BRD9 axis in squamous cell lung cancer.
•MiR-140-3p is down-regulated and correlated with tumor stage, smoking status and survival rates in SqCLC.•MiR-140-3p inhibits SqCLC cell proliferation and invasion both in cell lines and patient derived xenografts (PDX) models.•BRD9 is directly targeted and negatively correlated with miR-140-3p. Furthermore, BRD9 can rescue the phenotypes caused by miR-140-3p.•BRD9 is upregulated and promotes SqCLC cell proliferation and invasion by regulating c-myc in SqCLC cells.•Survival analysis indicates SqCLC patients whose tumors express higher levels of BRD9 have a worse prognosis.
•Urbanisation, energy consumption, and CO2 emissions relationship is investigated.•We present a panel model and a reduction potential analysis for China’s provinces.•Emissions of provinces in east ...region are much higher than that in central and west regions.•The three variables are found to have a positive bi-directional long run relationship.•Whilst China’s CO2 emissions will increase up to 2020, the potential for reductions is great.
Global warming resulting from rapid economic growth across the world has become a worldwide threat. The coordination of development of urbanisation, energy consumption, and carbon dioxide (CO2) emissions therefore forms an important issue; it has attracted considerable attention from both governments and researchers in recent years. This study investigated the relationship between urbanisation, energy consumption, and CO2 emissions over the period 1995–2011, using a panel data model, based on the data for 30 Chinese provinces. The potential to reduce CO2 emissions was also analysed. The results indicated that per capita CO2 emissions in China were characterised by conspicuous regional imbalances during the period studied; in fact, per capita CO2 emissions decrease gradually from the eastern coastal region to the central region, and then to the western region. Urbanisation, energy consumption, and CO2 emissions were found to present a long run bi-directional positive relationship, the significance of which was discovered to vary between provinces as a result of the scale of their respective economies. In addition, a bi-directional causal relationship was found to exist between urbanisation, energy consumption, and CO2 emissions: specifically, a bi-directional positive causal relationship exists between CO2 emissions and urbanisation, as well as between energy consumption and CO2 emissions, and a one way positive causal relationship exists from urbanisation to energy consumption. Scenario simulations further demonstrated that whilst China’s per capita and total CO2 emissions will increase continuously between 2012 and 2020 under all of the three scenarios developed in this study, the potential to achieve reductions is also high. A better understanding of the relationship between urbanisation, energy consumption, and CO2 emissions will help China to realise the low-carbon economic development.
Rapid urban expansion has profound impacts on global biodiversity through habitat conversion, degradation, fragmentation, and species extinction. However, how future urban expansion will affect ...global biodiversity needs to be better understood. We contribute to filling this knowledge gap by combining spatially explicit projections of urban expansion under shared socioeconomic pathways (SSPs) with datasets on habitat and terrestrial biodiversity (amphibians, mammals, and birds). Overall, future urban expansion will lead to 11-33 million hectares of natural habitat loss by 2100 under the SSP scenarios and will disproportionately cause large natural habitat fragmentation. The urban expansion within the current key biodiversity priority areas is projected to be higher (e.g., 37-44% higher in the WWF's Global 200) than the global average. Moreover, the urban land conversion will reduce local within-site species richness by 34% and species abundance by 52% per 1 km grid cell, and 7-9 species may be lost per 10 km cell. Our study suggests an urgent need to develop a sustainable urban development pathway to balance urban expansion and biodiversity conservation.
Polycyclic aromatic hydrocarbons (PAHs) are a large group of organic compounds which are comprised of two or more fused benzene rings. As a typical environmental pollutant, PAHs are widely ...distributed in water, soil, atmosphere and food. Despite extensive researches on the mechanisms of health damage caused by PAHs, especially their carcinogenic and mutagenic toxicity, there is still a lack of comprehensive summarization and synthesis regarding the mechanisms of PAHs on the gut-testis axis, which represents an intricate interplay between the gastrointestinal and reproductive systems. Thus, this review primarily focuses on the potential forms of interaction between PAHs and the gut microbiota and summarizes their adverse outcomes that may lead to gut microbiota dysbiosis, then compiles the possible mechanistic pathways on dysbiosis of the gut microbiota impairing the male reproductive function, in order to provide valuable insights for future research and guide further exploration into the intricate mechanisms underlying the impact of gut microbiota dysbiosis caused by PAHs on male reproductive function.
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•PAHs reshape gut-testis axis, impacting male reproductive balance.•PAHs influence sperms quality, quantity, and sex hormones in intricate ways.•Summarized the literature on how PAHs affect distal organs through gut microbiota.
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•Cu/SAC305/Cu joints after first reflow under TG showed remarkable heredity effect.•TG inducing gene clusters, deeper and narrower cavities was key for heredity effect.•Cu/SAC305/Cu ...joints showed non-heredity effect during isothermal multi-reflow.•Cu/Sn/Cu joints showed non-heredity effect due to the absence of gene clusters.•255 °C was the critical peak reflow temperature for the heredity effect existence.
The strategies for inducing heredity of β-Sn texture and thus controlling β-Sn orientation in micro solder joints during multi-reflow process were investigated. The temperature gradient (TG) induced gene clusters that carried the information similar to the solid-state crystals and conical cavities that provided preferred nucleation sites at one side of the joints were identified as the keys for generating heredity effect. There was non-heredity effect in Cu/Sn/Cu joints whether the joints were reflowed under TG or not for the first time due to the absence of gene clusters and in Cu/Sn-3.0Ag-0.5Cu(SAC305)/Cu joints during isothermal multi-reflow due to the absence of deep and narrow conical cavities. However, the Cu/SAC305/Cu joints that had orientated β-Sn grains after the first reflow under TG exhibited remarkable heredity effect during the subsequent second and third reflow. The critical peak reflow temperature was confirmed to be 255 °C over which the heredity effect disappeared. A general guidance of the strategies for inducing heredity effect in Cu/SAC305/Cu joints during multi-reflow process was demonstrated focusing on reflow temperature, times, duration, cooling rate and TG. The novel reflow method is believed to be beneficial to improve the reliability and anisotropy of micro solder joints containing few β-Sn grains.
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