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Acquired immunodeficiency syndrome (AIDS) caused by Human immunodeficiency virus type 1 (HIV-1) has a high tendency among illicit drug abusers. Recently, it is reported that abuse of fentanyl, a potent synthetic μ receptor-stimulating opioid, is an independent risk factor for HIV-1 infection. However, the mechanism of action in augmenting HIV-1 infection still remains elusive. In this study, we found that fentanyl enhanced infection of HIV-1 in MT2 cells, primary macrophages and Jurkat C11 cells. Fentanyl up-regulated CXCR4 and CCR5 receptor expression, which facilitated the entry of virion into host cells. In addition, it down-regulated interferon-β (IFN-β) and interferon-stimulated genes (APOBEC3F, APOBEC3G and MxB) expression in MT2 cells. Our findings identify an essential role of fentanyl in the positive regulation of HIV-1 infection via the upregulation of co-receptors (CXCR4/CCR5) and downregulation of IFN-β and ISGs, and it may have an important role in HIV-1 immunopathogenesis.

Quinazoline and its derivatives have drawn much attention in the development of potential antitumor agents. Here, we synthesized a series of 1,2,3-triazole derivatives of quinazoline at the C6 position and evaluated for their cytotoxic activity in various human cancer cell lines. We found that compound

Impairment of pulmonary function was evaluated in chronic bronchitis patients with preserved ratio impaired spirometry (PRISm). We retrospectively collected clinical data from 157 chronic bronchitis (CB) and 186 chronic obstructive pulmonary disease (COPD) patients between October 2014 and September 2017. These patients were assigned to three groups: control (normal pulmonary function), PRISm (forced expiratory volume in 1 second [FEV1]/forced vital capacity [FVC] ≥ 0.7, FEV1 p < 0.001 , maximal expiratory flow (MEF) 25% p < 0.001 , MEF50% p < 0.001 , maximal midexpiratory flow (MMEF) 25–75% p < 0.001 , residual volume (RV)/total lung capacity (TLC; p < 0.001 ), FVC% p < 0.001 , total respiratory resistance and proximal respiratory resistance (R5-R20; p < 0.001 ), respiratory system reactance at 5 Hz (X5; p < 0.001 ), resonant frequency (Fres; p < 0.001 ), and area of reactance (Ax; p < 0.001 ). However, the predicted FEV1% and RV/TLC were similar between the PRISm and COPD groups ( p = 0.992 and 0.122, respectively). PRISm is a nonspecific pattern of pulmonary function that indicates small airway dysfunction and may increase the risk of transformation to obstructive ventilation dysfunction. This trial is registered with ChiCTR-OCH-14004904.

Damage-associated molecular patterns secreted from activated kidney cells initiate the inflammatory response, a critical step in the development of sepsis-induced acute kidney injury (AKI). However, the underlying mechanism remains to be clarified. Here, we established a mouse model of sepsis-induced AKI through intraperitoneal injection of lipopolysaccharide (LPS) and demonstrated that LPS induced dramatical upregulation of C-C motif chemokine ligand 2 (CCL2) at both the mRNA and protein levels in the kidney, which was mainly expressed by tubular epithelial cells (TECs), especially by proximal TECs. Proximal tubule-specific ablation of CCL2 reduced LPS-induced macrophage infiltration, proinflammatory cytokine expression, and attenuated AKI. In vitro, using a Transwell migration assay, we found that deficiency of CCL2 in TECs decreased macrophage migration ability. However, myeloid-specific depletion of CCL2 could not protect the kidneys from the aforementioned effects. Mechanistically, LPS activated Toll-like receptor (TLR)2 signaling in TECs, which induced activation of its downstream effector NF-κB. Blockade of TLR2 signaling or inhibition of NF-κB activation in TECs significantly suppressed LPS-induced CCL2 expression. Furthermore, chromatin immunoprecipitation analyses confirmed a direct binding of NF-κB p65 in the CCL2 promoter region, and LPS increased the binding of NF-κB p65 to the CCL2 promoter, suggesting that TLR2/NF-κB p65 regulates CCL2 expression in TECs. Together, these results demonstrate that endogenous CCL2 released from proximal TECs, not from myeloid cells, was responsible for sepsis-induced kidney inflammation and AKI. Specifically targeting tubular TLR2/NF-κB/CCL2 signaling may be a potential therapeutic strategy for the prevention or attenuation of septic AKI.

As an important electrical connection component in electrical equipment, the strap contact is directly related to the long-term operation stability of equipment. The electrical contact resistance (ECR) of the electrical connection structure is an important indicator for evaluating the reliability of the electrical contact system. In this research, the theoretical calculation of ECR of the strap contacts used by the G-W theoretical model and the fractal theoretical model is improved and compared. After comparison with the experimental measurement values, the rationality and accuracy of the two theoretical models are discussed. The results show that when the load is small (1–3 N), the maximum error of G-W model is 41%, while the fractal model method has a maximum error of 9%. When the load is large (4–10 N), the results of the two are almost the same, and the errors are both within 14%. In summary, the error range of the fractal model is smaller and the change trend is closer to the experimental value, which is suitable for a relatively better ECR analytical calculation theory. The research results can provide a theoretical basis for research on the electrical contact performance of the electrical contact structure of electrical equipment.

To investigate the effect of pentoxifylline (PTX) on Chlorine (Cl2)-induced acute lung injury (ALI) by single-cell RNA sequencing (scRNA-seq). Female BALB/c mice were exposed to Cl2 at 400 ppm for 15 min. H&E staining was used to observe the degree of lung injury. scRNA-seq was conducted to analysis of normal and Cl2-exposed mice lung tissues. Immunofluorescence was used to observe genes of interest. Thirty-two mice were randomly divided into four groups: Control, Cl2, Cl2+Fer-1, Cl2+PTX. TEM, WB and ELISA were used to detect ferroptosis-related indicators. The 5, 8, 10, 12, 16, 20 clusters were epithelial cells and 4, 15, 18, 19, 21 clusters were endothelial cells. Pseudo-time analysis revealed the differentiation trajectory of epithelial cells and key regulatory genes (Gclc, Bpifa1, Dnah5 and Dnah9) during the process of injury. Cell–cell communication analysis identified several important receptor–ligand complexes (Nrp1-Vegfa, Nrp2-Vegfa, Flt1-Vegfa and Flt4-Vegfa). Ferroptosis were found up-regulated in epithelial and endothelial cells by GSVA analysis. Highly expressed genes to which closely related ferroptosis were found by SCENIC analysis. PTX could significantly decrease the levels of MDA and abnormal high expression of solute carrier family 7 member 11 (SLC7A11, the key transporter of cystine) as well as increase the expression of GSH/GSSG and glutathione peroxidase 4 (GPX4) (p 2-induced ALI. PTX may be a potential specific drug by inhibiting the process of ferroptosis in epithelial and endothelial cells.

Methylsulfonylmethane (MSM) is a natural organic sulfur component that has anti-inflammatory and antioxidant properties. In this study, injury of porcine intestinal epithelial cell (IPEC-J2) models were used to investigate the effect of MSM on lipopolysaccharide (LPS)-induced porcine intestinal epithelium barrier damage. The results of the cell cycle showed that the cells in the G2/M phase decreased significantly with the supplementation of 300 mmol/L MSM ( P

Affected by an insufficient understanding of oxidation characteristics and the CO production mechanism in low-rank coal goaf, the safety management of coal spontaneous combustion (CSC) faces severe challenges. In this study, in-depth research was conducted using ambient temperature oxidation (ATO), temperature-programmed, in situ FTIR experiments and DFT simulation after analyzing the oxidation scenario characteristics of low-metamorphic coal goaf. The results show the oxidation of low-rank coal goaf includes two processes of ATO in the dissipation zone and CSC in the oxidation zone. The CO production of ATO increases with a decrease in coal metamorphic degree, and the risk of CSC is influenced by ATO, with an inhibitory effect before the critical temperature, and an encouraging effect after that. The CO production mechanism of low metamorphic coal goaf from ATO to CSC is established. Before the critical temperature, CO mainly comes from the primary aldehyde functional groups, then peroxide-free radicals participate in the reaction, resulting in the production of a large number of secondary aldehyde functional groups, which leads to the sudden change in CO output. The problem of the abnormal, continuous exceedance of CO in the tailgate corner can be solved by developing an ATO inhibitor, which plays an inhibiting role at ambient temperature and decomposes in the event of CSC.

Cocrystallization integrates the merits of high energy and insensitivity between energetic molecules to obtain energetics with satisfying performance. However, how to obtain supramolecular synthons accurately and rapidly for predicting the structure and property of cocrystal remains a challenging problem. In this research, an efficient systematic search approach to predict CL-20/2,4-DNI cocrystal has been proposed that 2,4-DNI revolves around CL-20 with a stoichiometric ratio of 1:1 in accordance with the specified rules (hydrogen bond length: 2.2–3.0 A; search radius: 6.5 A; the number of hydrogen bond: 1–3). Eight possible supramolecular synthons were obtained by combining quantum chemistry with molecular mechanics. Crystal structure prediction indicated that there are four structures in cocrystal, namely P21/c, P212121, Pbca and Pna21, and CL-20/2,4-DNI cocrystal is likely to be P21/c and the corresponding cell parameters are Z = 4, a = 8.28 A, b = 12.17 A, c = 20.42 A, α = 90°, β = 96.94°, γ = 90°, and ρ = 1.9353 g/cm3. To further study the intermolecular interaction of CL-20/2,4-DNI cocrystal, a series of theoretical analyses were employed including intermolecular interaction energy, electrostatic potential (ESP), Density of State (DOS), Hirshfeld surface analysis. The C–H⋯O hydrogen bonds are demonstrated as the predominant driving forces in the cocrystal formation. The mechanical properties and detonation properties of CL-20/2,4-DNI cocrystal implies that the cocrystal shows better ductility and excellent detonation performances (9257 m/s, 39.27 GPa) and can serve as a promising energetic material. Cocrystal structure predicted was compared with the experimental one to verify the accuracy of systematic search approach. There is a less than 8.8% error between experiment and predict results, indicating the systematic search approach has extremely high reliability and accuracy. The systematic search approach can be a new strategy to search supramolecular synthons and identify structures effectively and does have the potential to promote the development of energetic cocrystal by theoretical design.

Sleeve lobectomy is recognized as an alternative surgical operation to pneumonectomy because it preserves the most pulmonary function and has a considerable prognosis. In this study, we aimed to investigate the implications of residual status for patients after sleeve lobectomy.In this retrospective cohort study, we summarized 58 242 patients who underwent surgeries from 2015 to 2018 in Shanghai Chest Hospital and found 456 eligible patients meeting the criteria. The status of R2 was excluded. The outcomes were overall survival (OS) and recurrence-free survival (RFS). We performed a subgroup analysis to further our investigation.After the propensity score match, the baseline characteristic was balanced between two groups. The survival analysis showed no significant difference of overall survival and recurrence-free survival between R0 and R1 groups (OS: p = 0.053; RFS: p = 0.14). In the multivariate Cox analysis, we found that the margin status was not a dependent risk factor to RFS (p = 0.119) and OS (p = 0.093). In the patients of R1, N stage and age were closely related to OS, but we did not find any significant risk variable in RFS for R1 status. In the subgroup analysis, R1 status may have a worse prognosis on patients with more lymph nodes examination. On further investigation, we demonstrated no differences among the four histological types of margin status.In our study, we confirmed that the margin status after sleeve lobectomies was not the risk factor to prognosis. However, patients with more lymph nodes resection should pay attention to the margin status.

Acute kidney injury (AKI) is a life-threatening condition that is one of most common side effects of cisplatin therapy. Fatty acid oxidation (FAO) is the main source of energy production in kidney proximal tubular epithelial cells (PTECs) but it is inhibited in AKI. Recent work demonstrated that activation of the farnesoid X receptor (FXR) protects against AKI, but the underlying mechanism remains elusive. Using a model of cisplatin-induced AKI, we found that FXR and FAO-related genes were remarkably downregulated while kidney lipid accumulated. Proximal tubule-specific or whole body FXR knockout worsened, while pharmacological activation attenuated these effects. Conversely, FXR knockout in non-proximal tubules did not. RNA-sequencing of PTECs demonstrated increased transcripts involved in metabolic pathways in cells overexpressing FXR versus control after cisplatin treatment, specifically transcripts associated with FAO and peroxisome proliferator-activated receptor-γ (PPARγ) signaling. Furthermore, FXR overexpression or activation improved FAO and inhibited intracellular lipid accumulation in cisplatin-treated cells. In vivo studies have shown that pharmacological activation of PPARγ can prevent cisplatin-induced lipid accumulation, kidney tubule injury and kidney function decline. However, inhibition of PPARγ eliminated the protective effects of FXR compared to control mice during the cisplatin treatment phase and after ischemia-reperfusion injury. Consistent with findings in vivo, FXR/PPARγ reduced lipid accumulation by improving FAO in cisplatin-treated cells. Furthermore, the inhibition of carnitine palmitoyltransferase 1α abolished the protective effect of FXR in cisplatin-treated mice. Thus, FXR improves FAO and reduced lipid accumulation via PPARγ in PTECs of the kidney. Hence, reconstruction of the FXR/PPARγ/FAO axis may be a novel therapeutic strategy for preventing or treating AKI.

Under the effects of complex geological and stress environments, burst hazards continue to be a major challenge for underground space utilization and deep resources exploration as its occurrence can lead to personnel causalities, equipment damage and structural collapse. Considering the stress path experienced by in-situ coal body, cyclic loading appears in quite various forms for instance shearer cutting, overlying strata breakage, hydro-fracturing and blasting, during tunnel, mining and underground space utilizing process. The stability of the underground coal body subject to periodic loading/unloading stress is extremely important for maintain the function of designed engineering structure for waste storage, safe mining, roadway development, gas recovery, carbon sequestration and so on. The mechanical properties of hard rock subject to cyclic fatigue loads has been intensively investigated by many researchers as the rock burst induced by supercritical loads has long been a safety risk and engineering problems for civil and tunneling engineering under deep overburden. More recently, the mechanical properties of coal samples under cyclic fatigue loads is investigated from the aspect of hysteresis, energy dissipation and irreversible damage as the burst hazards of brittle coal is rising in many countries. However, the crack propagation and fracture pattern of brittle coal need more research to understand the micro mechanism of burst incubation subject to cyclic fatigue loads as brittle coal can store more elastic strain energy and rapidly release the energy when its ultimate strength once reached. This research studied the internal crack status corresponding to different cyclic fatigue loading stage of brittle coal samples. The AE monitoring was applied during the uniaxial and cyclic loading process of brittle coal samples to record the crack intensity of samples at different loading stages. The damage evolution curve corresponding to loading status was then determined. The fracture pattern of coal samples determined by micro-CT scan was observed and discussed. It has been found by this paper that brittle coal of uniaxial compression tests demonstrated sudden failure caused by major splitting fracture while that of cyclic fatigue tests experienced progressive failure with mixture fracture network.

AIM: HIV infection is currently an incurable disease characterized by life-long drug utility. Its incurable causality and mechanism are still unknown to us. METHODS: To overcome this therapeutic setback, some breakthroughs should be made by utilizing different approaches. How to plan some experimental and clinical novelty for HIV curability is a modern challenge. In this article, new ideas and approaches for global HIV/AIDS therapeutic strategies are proposed and represented by scientific insights. RESULTS: Pharmaceutical characteristics, herbal medicine, novel drug targets, cutting-edge biotherapy, drug combination, animal modalities, and immune-stimuli for HIV latency, as well as clearance, are highlighted. DISCUSSION: To elucidate our understanding of curative treatment for HIV/AIDS, many new pathological discoveries, expansion, technical advances, and potential drug targets are constructed. After the discovery of novel pathogenesis and therapeutic evolution, HIV/AIDS therapeutic curability may become achievable and a reality. CONCLUSION: Transformation from animal model investigation to widespread therapies for larger volume of human population is a necessity in modern medicine. In this infectious treatment scenario, major breakthroughs in medicine and drug development are anticipated.

We construct a theoretical model to interpret the structural shock from the COVID-19 pandemic and the response of local labour market and industry specialization. The empirical study takes the large-scale online labour market of China to analyse firms’ hiring demand for 20 industries across 380 cities with monthly recruitment data from May 2017 to September 2020. Post-event quantitative analysis on job postings and employer demand highlighted that the pandemic resulted in an unemployment shock and industry- and city-level redistribution of the worker. China’s local job market resilience also revealed a regional imbalance, correlated with pandemic risk, city scale and industry structure.

Herein we described a catalytic epoxidation of α,β-enone with peroxide in situ generated via a predominant single electron transfer and a minor energy transfer pathways using inexpensive natural vitamin B2...

α-Keto ketals and benzannulated oxo-spiroketals have been regioselectively synthesized using a Sc3+-coordinated riboflavin tetraacetate photocatalyst with electron-deficient alkynes and alkynediols, respectively.

PurposeAs majority of studies of employee ownership (EO) take place in developed markets and primarily focus on the impact on firm performance, scholars have recently called for other markets, especially large developing markets to be considered, as well as alternative outcome measures.Design/methodology/approachThrough the examination of the implementation of EO by Chinese listed firms during the period of 2011–2019 with total 3,473 firms and 21,204 observations, the authors provide empirical evidence on the positive effect of EO on firm R&D investment within the rapidly growing Chinese market.FindingsThe authors find that the adoption of EO promotes higher level of firm R&D investment. This positive relationship is more evident among small firms, non-state-owned firms and local state-owned-firms, compared with their counterparts. As for the plausible channels, the authors find that adopting EO provides a favorable institutional environment, which attracts more technical staff, improves workplace quality, and encourages job stability and greater employee effort, leading to greater R&D investment.Originality/valueThough the connection between R&D investment/innovation and firm survival performance has been known for decades, the innovation side of outcomes has been ignored by EO research. Therefore, the authors explore the relationship between EO implementation and firm R&D investment within the rapidly growing Chinese market.

As mining progresses into deep ore deposits in Australia, geo-hazards such as coal burst and outbursts are becoming a major concern for mine workers. The occurrence of geo-hazards involved the ejection of coal lumps and sometimes large volumes of hazardous gases such as methane and carbon dioxide. Whilst it is extremely important to de-stress and de-gas the seam and adjacent strata before roadway development and install competent support systems such as steel mesh and bolt, the last line of protection will be the installation of a protective canopy on the Continuous Miner (CM), which is typically used for roadway developments, to shield mine workers from these deadly dynamic impacts of coal and rock resulting from a burst or outburst. This paper aims to introduce the design, manufacture and testing of an innovative modular protective structure on the CM in underground coal mines. The developed protective system can be easily assembled in the underground mining environment and provide a high level of protection against flying debris hazards in the event of a coal burst. The extensive experimental program and numerical simulations have confirmed the high performance of the protective system against high-speed impact loading by single and multiple coal rocks and projectiles.

There have been significant advancements in medical techniques in the present epoch, with the emergence of some novel operative substitutes. However, the treatment of tracheal defects still faces tremendous challenges and there is, as yet, no consensus on tracheal and carinal reconstruction. In addition, surgical outcomes vary in different individuals, which results in an ambiguous future for tracheal surgery. Although transplantation was once an effective and promising method, it is limited by a shortage of donors and immune rejection. The development of bioengineering has provided an alternative for the treatment of tracheal defects, but this discipline is full of ethical controversy and hindered by limited cognition in this area. Meanwhile, progression of this technique is blocked by a deficiency in ideal materials. The trachea together with the carina is still the last unpaired organ in thoracic surgery and propososal of a favorable scheme to remove this dilemma is urgently required. In this review, four main tracheal reconstruction methods, especially surgical techniques, are evaluated, and a thorough interpretation conducted., Tracheal and carinal reconstruction are still challenges in regenerative medicine although medical techniques have achieved significant advancements in the present epoch.

AIM: To investigate the effect of modified Zhujing pill on retinal thickness and apoptosis in form deprivation myopia(FDM)mice.METHODS: Totally 72 C57BL/6J mice aged 3-week-old were randomly divided into control group 1, model group 1, intervention group 1, control group 2, model group 2 and intervention group 2, with 12 mice in each group. The first three groups were tested for 3wk and the last three groups were tested for 6wk, except for the groups of control 1 and control 2, all the mice used translucent goggles to cover their right eyes for form deprivation. The mice of intervention 1 and intervention 2 were respectively given intragastric administration modified Zhujing pill suspension 0.546g/(kg·d)(0.1mL/d)for 3wk at the beginning and after 3wk of the experiment. Same amount of saline was given to mice in other groups at the same time of modeling. The eye axis was measured before and after the experiment. At the end of the experiment, the eye of mice was taken for HE staining to observe the thickness changes of each layer of retina. Immunohistochemistry(IHC)and western blotting(WB)were used to detect Bcl-2 and Caspase3 expression of protein.RESULTS: At the end of the experiment, the axis of model group 1 was significantly higher than that of control group 1(P

Coal and gas outburst is tightly related to the existence of tectonic coal. Because large blocks of tectonic coals are difficult to be collected, reconstituted coal specimens are often used to study the mechanical properties. In this study, reconstituted coal specimens were prepared under different external forces. Then, triaxial compression tests were conducted under different confining pressures. The deviatoric stress, volumetric strain, axial strain and dilatancy ratio were analyzed. From the laboratory tests, the cohesion of reconstituted coal is positively related to the applied external force. Bonds are developed between coal particles. It is found that the deviatoric stress mainly contributes to bond breakage and internal friction. Under low confining pressure testing condition, the specimen is in over-consolidation state. The failure process is similar to the failure of intact coal. The deviatoric stress reaches the peak value. Then a strain-softening effect is observed with the bond breakage. But for normal consolidation scenario, the bond-breakage stress is smaller than the maximum internal friction force. With the increase of deviatoric stress, the shear stress exceeds the threshold limit value of bond breakage first and then, it exceeds the maximum internal force. Before the new unstable fracture development, extensive bond breakage happens. When the shear stress exceeds the maximum friction force, internal slippage occurs with sharp increases of dilatancy ratio. From this study, the failure behaviors of reconstituted coal are closely related to the stress conditions. The understanding of tectonic coal failure process is enhanced.

A Gram-stain-negative, aerobic, and yellow-pigmented bacterium, designated A3-108T, was isolated from seawater of the West Pacific Ocean. Cells were non-motile and rod-shaped, with carotenoid-type pigments. Strain A3-108T grew at pH 6.0–8.5 (optimum 6.5) and 15–40 °C (optimum 28 °C), in the presence of 0.5–10% (w/v) NaCl (optimum 1.0%). It possessed the ability to produce H2S. Based on the 16S rRNA gene analysis, strain A3-108T exhibited highest similarity with Aureisphaera salina A6D-50T (90.6%). Phylogenetic analysis shown that strain A3-108T affiliated with members of the family Flavobacteriaceae and represented an independent lineage. The principal fatty acids were iso-C15:0, iso-C17:0 3-OH, iso-C15:1 G, and summed feature 3 (C16:1ω7c and/or C16:1ω6c). The sole isoprenoid quinone was MK-6. The major polar lipids were phosphatidylethanolamine, one unidentified aminophospholipid, one unidentified aminolipid and one unidentified lipid. The ANIb, in silico DDH and AAI values among the genomes of strain A3-108T and three reference strains were 67.3–71.1%, 18.7–22.1%, and 58.8–71.4%, respectively. The G + C content was 41.0%. Distinctness of the phylogenetic position as well as differentiating chemotaxonomic and other phenotypic traits revealed that strain A3-108T represented a novel genus and species of the family Flavobacteriaceae, for which the name Luteirhabdus pelagi gen. nov., sp. nov. is proposed (type strain, A3-108T = CGMCC 1.18821T = KCTC 82563T).

Potato late blight caused by Phytophthora infestans is still one of the main factors limiting potato production. Epichloë spp. can provide host plants with various resistances, which makes them show great potential in the biological control of diseases. In this study, we explored the potential biological activity of crude extracts of 20 strains of Epichloë bromicola to control P. infestans. The crude extracts of strains 1 and 8 showed significant antifungal activity with an inhibition rate of 88% and 81%, respectively, and showed different effects on the mycelium morphology of P. infestans observed by scanning electron microscopy. Moreover, the two crude extracts demonstrated an interesting therapeutic and protective effect on potato late blight, and none of the extracts had an adverse effect against zebrafish embryos. A total of 13 metabolites were isolated from the crude extract of strain 8, and these tested compounds showed a weak antifungal effect and the inhibition rate was less than 80%. These findings suggested that strains 1 and 8 have potential for biocontrol of late potato blight.

This study aims to investigate the behavior of ground surface settlement in TBM double-line tunnels constructed under existing buildings and to devise a calculative representation for that behavior. Numerical simulation and field monitoring methods were used to examine the Zhongcong Tunnel in Chongqing Metro Line 9. The ground surface settlement was analyzed using an orthogonal test of 3D numerical simulation methods. The results showed that ground surface settlement was influenced by TBM tunneling parameters and the location of the existing building in the following manner. The existing building reduced the settlement trough width. Surface settlement was increased by frictional and palm surface thrust forces but reduced by grouting pressure. The settlement trough width of the first excavation iz correlated with that of the last excavation iy. To accommodate the influence of existing buildings, the tilt factor of the settlement trough TR was introduced to improve the formula for calculating the ground surface settlement of TBM double-line tunnels. The improved formula was validated by comparing the calculated results with actual measurements.

We study the impact of formal and informal institutions perceived and experienced by firms on their innovation using the 2012 World Bank Enterprise Survey data in China. We propose a framework to identify different innovator types of firms. Our analysis shows that (1) perceived constraints from the governmental system make firms more likely to be innovators than non-innovators; (2) perceived constraints from the legal system make firms more likely to be imitators than innovators; (3) lack of formal finance makes firms more likely to be non-innovators than innovators; (4) prevalence of bribery makes firms more likely to be non-innovators than innovators but less likely to be innovation pretenders than innovators. Our study enriches institutional theory and innovation research by establishing a framework that encompasses multiple dimensions of formal and informal institutions perceived and experienced by firms and the impacts of such perception and experience on firms’ propensity to become certain type of innovator.

The stability of underground rock engineering is strongly affected by cavities. To analyse the dynamic response and fracture evolution of rock mass containing cavities, intact specimens and those containing a single rectangular cavity or two rectangular cavities with different layouts were tested by using split Hopkinson pressure bar (SHPB) test system under three levels of nitrogen gas actuating pressures (0.35 MPa, 0.40 MPa and 0.45 MPa). During tests, failure process was recorded by a high-speed camera. Then, digital image correlation (DIC) techniques combined with displacement trend line method was employed to investigate the crack evolution and failure modes. Moreover, absorbed energy per unit volume was calculated to evaluate specimen fragmentation. Test results reveal that under a given impact pressure, the dynamic loading capacity is apparently higher for intact specimens than for those containing cavities. Although the incident energy has varying influence on the fragmentation of specimens in different cases, the crack evolution and failure modes seem to be independent on incident energy but mainly associated with cavity number and layout. The existence of cavities contributes to the degradation of dynamic loading capacity and absorbed energy. For specimens containing two cavities, the twin-cavity system with the connecting angle of 45° exhibits the maximum weakening effect on the mechanical parameters. In comparison, when the connecting angle is 90°, the specimens containing two cavities hold the maximum average dynamic loading capacity, which approximates that of the specimens containing a single cavity.

The fragmentation of coal produces abundant coal gases and is presumed to be the defining characteristic of coal and gas outbursts. Knowing the mechanism of these catastrophic hazards is one of the most important breakthroughs in mining geology. In the outburst process, coal spallation represents a unique failure type and typically leaves behind a spallation area (with a series of fracture textures) in the coal seam. Revealing its features and formation mechanism is crucial in accurately interpreting the outburst process. In this study, we conducted a series of outburst experiments with different gases, including CO2, N2, and He. We establish that a spallation area can develop spontaneously during CO2 and N2 tests, whereas an outburst caused by He tests (even under stressed conditions) does not produce a spallation area. That is, the spallation area cannot be observed in non-absorbable gas outbursts. We, therefore, focus on the role of coal gas in spallation and propose a viable mechanism to explain its formation. During the outburst development stage, the influence of gas ad-/desorption is critical, as it controls the width of the spallation area and the spallation thickness. In contrast, stress is not a necessary condition. Whether a spallation area will be produced is particularly determined by the generation of a sufficient internal pressure gradient. Moreover, because of gas desorption, the total outburst energy can be increased by 1.84–5.30 times; and the mean outburst propagation velocity and the mean frequency of coal spallation ejected can be enhanced by 0.38–8.76% and 1.28–12.07%, respectively. Consequently, the destructiveness of outbursts depends on the contribution of desorbed gas.

This paper presents a series of novel hybrid columns incorporating emerging materials, being the alternative to pumpable standing supports used in underground mines. The infill material of these hy...

This research reviewed the mechanics and gas desorption properties of intact coal, and tested the crushing work ratios of different intact coals, and then, studied the stress conditions for the failure or crushing of intact coal and the gas demand for the pulverization of intact coal particles. When a real-life outburst case is examined, the required minimum stress for intact coal outburst is estimated. The study concludes that the crushing work ratios of three intact coal samples vary from 294.3732 to 945.8048 J/m2. For the real-life case, more than 2300 MJ of transport work is needed, and 10062.09, 7046.57 and 5895.47 m3 of gas is required when the gas pressure is 1, 2 and 3 MPa, respectively. The crushing work exceeds the transport work and even reaches 13.96 times of the transport work. How to provide such an enormous crushing work is an energy-limiting factor for the outburst in intact coal. The strain energy is needed for the crushing work, and the required minimum stress is over 54.35 MPa, even reaching 300.44 MPa. These minimum stresses far exceed the in-situ vertical and horizontal stresses that can be provided at the 300–700 m mining depth range.

Effectively reducing manufacturing carbon dioxide (CO2) emissions is a vital strategy for China to curb its rapidly rising carbon footprint. Features of such a reduction in manufacturing include an increase in the share of high-tech manufacturing and optimization of the energy consumption structure. This study aims to analyze the case of Shenzhen, a unique post-industrial innovative manufacturing megacity, for its leading experience in China’s manufacturing transition. Disaggregated manufacturing emissions data of Shenzhen, including 27 sub-sectors in four categories, were collected, and driving factors were identified by the logarithmic mean Divisia index (LMDI) method. The results suggest that: (1) CO2 emissions from Shenzhen’s manufacturing show a phased difference between 2008–2012 and 2012–2020. CO2 emissions embodied in electricity consumption have increased by over 30% in the former period and have remained stable at a high level of over 90%. (2) Significant heterogeneity of CO2 emissions in various manufacturing sectors is revealed, with the largest emissions sources being factories that make communication equipment, computers, and other electronic equipment. (3) Lower carbon intensity is the primary factor in reducing CO2 emissions, while the economic activity effect of manufacturing possesses a stimulating impact. (4) The marginal impact of restructuring on CO2 emissions is insignificant since the manufacturing and energy structures of Shenzhen have been upgraded to a low carbon level. Therefore, strengthening the power saving management and improving the energy efficiency of the manufacturing, rather than optimizing the manufacturing and final energy structures, will be a necessary potential solution to the problem of how to reduce CO2 emissions in Shenzhen’s manufacturing.

Ground surface settlement under subway tunnel construction is one of the main sources of urban ground surface settlement, which may threaten the safety of existing buildings. Therefore, it is necessary to study the influence of subway tunnel construction on the safety and stability of surface subsidence. In the current study, the ground settlement originating from the operation of a tunnel-boring machine (TBM) while excavating a double-line tunnel that underpasses existing buildings is studied. To this end, numerical simulations were carried out and experimental data were analyzed. The boring parameters for the underpass interval section were derived by simulating the construction process and analyzing the TBM parameters in a real project. Then, the influence of thrust force, grouting pressure, and frictional force was considered on the surface settlement. For spatial locations between the existing buildings and the tunnel in the underpass area, the width of the ground surface settlement caused by different excavation sequences of the TBM two-line tunnel was analyzed. The obtained results demonstrate that the performed calculations are consistent with the monitoring data. It is found that the width and depth of the ground surface settlement trough are affected by the distance between the existing buildings and the TBM construction tunnel. However, the settlement location is independent of the excavated sequence but depends on the location of the TBM tunnel and the existing building.