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Concrete slump, a crucial indicator of fluidity, directly affects the pumpability and construction efficiency of concrete. Conventionally, concrete slumps are assessed through multiple test iterations conducted by skilled professionals to obtain accurate results. In this study, a predictive model was established to predict concrete slumps directly based on concrete mix proportions, thereby mitigating labor and time costs. An open-source dataset was used in this study. The selected water-cement ratio ranged from 0.29 to 0.66. Cement, slag, fly ash, water, superplasticizer, coarse aggregate, and fine aggregate were employed as input parameters. Furthermore, the performances of a variety of algorithms in predicting concrete slumps were analyzed and compared. The algorithms included SVM, KNN, Extra-Trees, Gradient Boosting, Decision Tree, Elastic Net, Lasso, Ridge, Random Forest, Bagging, AdaBoost, and XGBoost. Through a comprehensive comparison of the prediction performance of these models, AdaBoost, Bagging, Extra-Trees, and Random Forest were adopted as base models. Moreover, the SVM algorithm optimized using Differential Evolution was employed as a secondary model to construct an enhanced integrated prediction model. The final prediction model boasts an MSE of 2.099984, MAE of 1.225597, RMSE of 1.449132, and R2 of 0.970418. Compared to conventional prediction models, the proposed model has the potential to substantially improve prediction performance.

Abstract The coronavirus disease 2019 (COVID-19) brought a healthy crisis all around the world. It’s not only affected healthcare utilization, but also some disease’s incidence. We collected pre-hospital emergency data in Chengdu from January 2016 to December 2021, and studied the demand for emergency medical services (EMSs), emergency response times (ERTs), and the disease spectrum in the city proper of Chengdu as a whole. A total of 1,122,294 prehospital emergency medical service (EMS) instances met the inclusion criteria. Under the influence of COVID-19, notably in 2020, the epidemiological characteristics of prehospital emergency services in Chengdu were considerably altered. However, as the pandemic was brought under control, they returned to normal or even earlier in 2021.The COVID-19 pandemic had an effect on people's medical care-seeking behavior and the performance of prehospital emergency services. Although the indicators associated with prehospital emergency services eventually recovered as the epidemic was brought under control, they remained marginally different from before the outbreak.

AlGaN grown on a GaN template usually suffers tensile stress, and the accumulated tensile stress may cause formation of cracks. In this paper, a method to reduce the tensile stress during AlGaN growth by inserting an InGaN interlayer is proposed. Although InGaN has a larger in-plane lattice constant, it will not cause the subsequent growth of AlGaN to be subject to greater tensile stress if InGaN is coherently grown on AlGaN. On the contrary, due to the low thermal expansion coefficient of InGaN, the subsequent growth of AlGaN will suffer less tensile stress through an asymmetric temperature varying process. The validity of this method was verified by in-situ curvature monitor, reciprocal space mapping and temperature-dependent Raman spectral observation. In addition, it is found by atomic force microscopy and scanning electron microscopy that the insertion of InGaN interlayer introduces V-shaped pits into the AlGaN structure which can be refilled by later AlGaN growth. It is inferred that they may play additional role in stress release similar to what the patterned substrate usually does.

The leakage of the electronic current of a laser diode (LD) has some significant influences on the performance of the LD. In this study, commercial simulation software LASTIP is used to numerically evaluate the performances of LDs by using different wavelengths and Al contents of the electron blocking layer (EBL). These LDs a adopt multilayer structure, which contains cladding layers, waveguide layers, multiple quantum well layers, contact layers and an AlxGa1−xN EBL. The influence mechanism of EBL is theoretically examined by analyzing the simulated performances. It is found that for short-wavelength violet LDs, the electrical and optical properties of the LD will reach the optimum state when the Al content (x) in the EBL is nearly 0.25. For long-wavelength green LDs, it will achieve optimum electrical and optical properties when the Al content in the EBL is as low as possible. We also compare the simulation results of LDs with emission wavelengths in the range of violet and green, including blue cyan, for a more general evaluation. According to the simulated results, it is verified that the influence of the EBL’s Al content on LD performance enhances as the wavelength increases.

The luminescence mechanism of inhomogeneous InGaN/GaN multiple quantum wells (MQWs) grown by metal organic chemical vapor deposition (MOCVD) and the way to improve their optical properties are studied. Fluctuations in layer thickness and In content of QWs are found to lead to a blurring of the well/barrier interfaces and a deterioration of MQW’s quality which are checked by measuring transmission electron microscopy and energy dispersive x-ray spectroscopy. Moreover, the temperature-dependent photoluminescence (PL) spectra show that the luminescence homogeneity of MQWs becomes worse as the spectral line width broadens with increasing well thickness. In addition, the theoretical calculation results confirm that the polarization electric field in wider QWs is stronger than that in narrower QWs, and the stronger polarization electric field tilts the energy band and enhances the quantum confinement Stark effect, causing wavelength redshift, which is confirmed by the measurement results of PL mapping. Based on the analysis of inhomogeneity in the MQWs, the thickness of the first QW along the growth direction is especially recommended not to be too thick then it act as a pre-stress modulator to improve the luminescence efficiency of InGaN/GaN MQWs.

Abstract Background Open reduction and internal fixation (ORIF) is the preferred choice for treating clavicle fractures. The brachial plexus injury caused by ORIF of a clavicle fracture is very rare. If it is not treated in time, the function of the brachial plexus will be challenging to recover, which will eventually lead to upper limb dysfunction and seriously affect the patient’s quality of life. Our team recently used ORIF to treat a patient with a clavicle fracture, who developed brachial plexus injury symptoms after surgery. Case presentation A 34-year-old female patient was admitted to the hospital for 13 h due to the right shoulder movement restriction after a fall. Due to the significant displacement of the fracture, we used ORIF to treat the fracture. The surgery went well. When the anaesthesia effect subsided 12 h after the operation, the patient developed right brachial plexus injury symptoms, decreased right upper limb muscle strength, dysfunction, and hypoesthesia. Symptomatic treatments, such as nourishing nerve and electrical stimulation, were given immediately. Sixty days after the operation, the patient’s brachial plexus injury symptoms disappeared, and the function of the right upper limb returned to the preoperative state. Conclusions Patients with clavicle fractures usually need to undergo a careful physical examination before surgery to determine whether symptoms of brachial plexus injury have occurred. Anaesthesia puncture requires ultrasound guidance to avoid direct damage to the brachial plexus. When the fracture end is sharp, reset should be careful to prevent nerve stump stabbed. When using an electric drill to drill holes, a depth limiter should be installed in advance to prevent the drill from damaging the subclavian nerve and blood vessels. When measuring the screw depth, the measuring instrument should be close to the bone surface and sink slowly to avoid intense hooks and damage to the brachial plexus. Try to avoid unipolar electrosurgical units to prevent heat conduction from damaging nerves, and bipolar electrocoagulation should be used instead. If symptoms of brachial plexus injury occur after surgery, initial symptomatic treatment is drugs and functional exercise, and if necessary, perform surgical exploration.

This study explores the relationship between ESG investments and carbon emissions in China. Our results show that 1% increase in environmental investments would cause 0.246% decrease in CO2 emissions and 0.558% decrease in carbon emission intensity. The impact of ESG investment is heterogeneous across the developed and underdeveloped regions. Environmental investments in the advanced eastern region have significantly improved carbon productivity. In contrast, environmental investments in the central and western regions significantly reduced carbon emissions, but they have little impact on carbon productivity.

As an integral part of economic trade, energy trade is crucial to international dynamics and national interests. In this study, an international energy trade network is constructed by abstracting countries as nodes and representing energy trade relations as edges. A variety of indicators are designed in terms of networks, nodes, bilaterals, and communities to analyze the temporal and spatial evolution of the global energy trade network from 2001 to 2020. The results indicate that network density and strength have been steadily increasing since the beginning of the 21st century. It is observed that the position of the United States as the core of the international energy market is being impacted by emerging developing countries, thus affecting the existing trade balance based on topological analysis. The weighted analysis of bilateral relations demonstrates that emerging countries such as China, Brazil, and Saudi Arabia are pursuing closer cooperation. The community analysis reveals that an increasing number of countries possess strong energy trade capabilities, resulting in a corresponding increase in energy trade volumes.

We have demonstrated the role of thermal annealing treatment after InGaN quantum well layer growth to improve the interface morphology and luminescence properties of InGaN/GaN multiple quantum wells (MQWs). X-ray diffraction and transmission electron microscope analyses reveal that better structural properties are achieved by appropriately increasing the ramp-up time as well as relatively decreasing the annealing temperature as the interface quality of MQWs is improved. Moreover, the photoluminescence (PL) and electroluminescence (EL) measurements confirm the higher crystal quality and optical properties of InGaN/GaN MQWs. The reason may be the redistribution of indium atoms improves the homogeneity of localized states in MQWs, and the In-rich clustering behavior is obviously alleviated. This annealing method is feasible and can lead to obtaining high-performance semiconductor optoelectronic devices.

The modeling of the deformation and failure process of a cyclotetramethylene tetranitramine modified double-base (HMX-MDB) propellant based on the microstructure is of great importance for its manufacturing process and storage lifetime. In the present work, the debonding, nucleation, and crack propagation in an HMX-MDB propellant were investigated experimentally and numerically. Stress-strain responses and viscoelastic parameters were obtained through uniaxial tensile tests on the HMX-MDB propellant and stress relaxation tests on a nitrocellulose-nitroglycerine (NC-NG) propellant, respectively. A two-dimensional representative volume element (RVE) model was developed based on the molecular dynamics method by embedding HMX particles in the NC-NG matrix. A zero-thickness cohesive element was used to simulate the damage behavior of the matrix and the interface. A piecewise cohesive zone model (PCZM) was established to capture stress-strain responses resulted from the matrix rupture and the debonding process at the particle-matrix interface. The effects of matrix strength and interface strength on the mechanical properties of the HMX-MDB propellant were investigated by PCZM. The different ratio of matrix strength to interface strength revealed three kinds of HMX-MDB propellant’s damage patterns: matrix cracking, matrix cracking followed by particle-matrix interfacial debonding, and particle-matrix interfacial debonding followed by matrix cracking.

Organic macerals are the basic components of organic matter and play an important role in determining the hydrocarbon generation capacity of source rock. In this paper, organic geochemical analysis of shale in the Chang 7 member of the Yanchang Formation was carried out to evaluate the availability of source rock. The different organic macerals were effectively identified, and the differences in hydrocarbon generation and pore-forming capacities were discussed from two perspectives: microscopic pore development and macroscopic hydrocarbon generation through field emission scanning electron microscopy (FE-SEM) and energy-dispersive spectrum (EDS) analyses, methane isotherm adsorption, and on-site analysis of gas-bearing properties. The results show that the source rock of the Chang 7 member has a high abundance of organic matter and moderate thermal evolution and that the organic matter type is mainly type I. Based on the morphology of the organic matter and the element and pore development, four types of hydrogen-rich macerals, including sapropelite and exinite, and hydrogen-poor macerals, including vitrinite and inertinite, as well as the submacerals, algae, mineral asphalt matrix, sporophyte, resin, semifusinite, inertodetrinite, provitrinite, euvitrinite, and vitrodetrinite, can be identified through FE-SEM and EDS. A large number of honeycomb-shaped pores develop in sapropelite, and round-elliptical stomata develop in exinite, while vitrinite and inertinite do not develop organic matter pores. The hydrogen-rich maceral is the main component of organic macerals in the Chang 7 member of the Yanchang Formation. The weight percentage of carbon is low, so it has good hydrocarbon generation capacity, and the organic matter pores are developed and contribute 97% of the organic matter porosity, which is conducive to hydrocarbon generation and storage. The amount of hydrogen-poor maceral is low, and the weight percentage of carbon is low, and the organic matter pores are not developed, which is not conducive to hydrocarbon generation and storage.

Shale is a typical fine-grained sedimentary rock with small grain sizes of matrix components, significant lithofacies variation of rock texture and structure, and strong heterogeneity of organic matter and mineral compositions. Characterization of mineral compositions and their heterogeneity in micro- to nanoscale are the key parameters to gas shale pore structure and rock physical properties. In order to study the microscale mineralogy heterogeneity of the lacustrine shales in the Triassic Yanchang Formation in the Ordos Basin, the micro-Fourier transform infrared spectroscopy (micro-FTIR) technique was conducted. Based on the specific micro-FTIR spectra peaks, the abundance of mineral compositions can be quantitatively determined in the selected microscale areas. The results show that within the range of 80 μm micro-FTIR test interval, both massive argillaceous shale and silty interlayered shale show obvious heterogeneity; in particular, the relatively homogeneous shale observed by the naked eyes also has strong mineral heterogeneity. The results of micro-FTIR spectra are basically consistent with the bulk X-ray diffraction (XRD) data. The advantage of this micro-FTIR technique includes higher resolution (less than 100 μm) and in situ mineral characterization of shale samples at micro- and nanoscale.

3-bromo-4,5-Bis(2,3-dibromo-4,5-dihydroxybenzyl)-1,2-benzenediol (CYC31) is a bromophenol protein tyrosine phosphatase 1B (PTP1B) inhibitor isolated from the red alga Rhodomela confervoides. Here, the effect of CYC31 on the insulin signaling and fatty-acid-induced disorders in C2C12 myotubes was investigated. Molecular docking assay showed that CYC31 was embedded into the catalytic pocket of PTP1B. A cellular study found that CYC31 increased the activity of insulin signaling and promoted 2-NBDG uptake through GLUT4 translocation in C2C12 myotubes. Further studies showed that CYC31 ameliorated palmitate-induced insulin resistance in C2C12 myotubes. Moreover, CYC31 treatment significantly increased the mRNA expression of carnitine palmitoyltransferase 1B (CPT-1B) and fatty acid binding protein 3 (FABP3), which was tightly linked with fatty acid oxidation. These findings suggested that CYC31 could prevent palmitate-induce insulin resistance and could improve fatty acid oxidation through PTP1B inhibition.

The urban rail transit line operating in the express and local train mode can solve the problem of disequilibrium passenger flow and space and meet the rapid arrival demand of long-distance passengers. In this paper, the Logit model is used to analyze the behavior of passengers choosing trains by considering the sensitivity of travel time and travel distance. Then, based on the composition of passenger travel time, an integer programming model for train stop scheme, aimed at minimizing the total passenger travel time, is proposed. Finally, combined with a certain regional rail line in Shenzhen, the plan is solved by genetic algorithm and evaluated through the time benefit, carrying capacity, and energy consumption efficiency. The simulation result shows that although the capacity is reduced by 6 trains, the optimized travel time per person is 10.34 min, and the energy consumption is saved by about 16%, which proves that the proposed model is efficient and feasible.

Activated macrophages play a vital role in rheumatoid arthritis (RA) pathophysiology. CD44 is an overexpressed receptor on activated macrophages that is a potential target site for RA treatment. In this study, we prepared hyaluronic acid (HA) coated acid-sensitive polymeric nanoparticles (HAPNPs) composed of egg phosphatidylcholine, polyethylenimine, and poly (cyclohexane-1,4-diyl acetone dimethylene ketal) (PCADK) loaded with dexamethasone (Dex) for the treatment of RA. PCADK was used to form polymeric cores because of its acid-sensitivity. The HAPNPs were about 150 nm in size and had a zeta potential of −2.84 mV. The release rate of Dex from HAPNPs/Dex in vitro increased markedly when the pH decreased from 7.4 to 4.5, indicating that the HAPNPs were pH-sensitive. In a cellular uptake study, stronger fluorescence signals were observed in activated macrophages treated with HAPNPs, suggesting that HAPNPs could be effective nanodevices target to activated macrophages. In rats with adjuvant-induced arthritis, HAPNPs could inhibited the progression of RA. Taken together, these results suggest that the HAPNPs could be useful in RA therapy.

Cisplatin is a commonly used drug for chemotherapy, however, whether it may be used synergistically with radiotherapy remains unclear. The present study investigated the underlying mechanisms of synergistic killing by radiosen-sitization and cisplatin, with a focus on the growth inhibition, apoptosis and autophagy of non-small cell human lung cancer cells in vitro and in a tumor xenograft in vivo. A549 cells were used for the in vitro experiments and divided into the following four treatment groups: Sham-irradiated; conventional radiotherapy (CRT) of five doses of 2 Gy every day; hyperfrac-tionated radiotherapy of five doses of 2 Gy (1 Gy twice a day at 4 h intervals) every day; and CRT plus cisplatin. A xenograft tumor-bearing C57BL/6 model was established for the in vivo experiments and the above-mentioned treatments were administered. MTT and colony formation assays were used to detect cell viability and western blotting was performed to detect the levels of protein expression. Monodansylcadaverine staining and the immunofluorescence technique were used to analyze the autophagy rate, while flow cytometry and immunohisto-chemistry were performed to detect the expression levels of the genes associated with apoptosis and autophagy, including microtubule-associated protein 1 light chain 3 (MAPLC3)-II, phosphoinositide 3-kinase (PI3K) III, Beclin1, phosphorylated protein kinase B (p-AKT), damage-regulated autophagy modulator (DRAM), B-cell lymphoma 2 (Bcl-2), Bcl-2-associated X protein, caspase-3 and p21. The MTT assay demonstrated that cisplatin exhibits a dose-dependent cytotoxicity in A549 cells and synergizes with radiation to promote the cell-killing effect of radiation. In the xenograft mouse model of Lewis cells, cisplatin plus ionizing radiation (IR) (five doses of 2 Gy) yielded the most significant tumor suppression. The autophagic vacuoles, the ratio of MAPLC3-II to MAPLC3-I (LC3-II/LC3-I) and the levels of Beclin1 were found to increase in all treatment groups, with the most marked upregulation observed in the CRT plus cisplatin treatment group. In addition, caspase-3 processing was enhanced in the group treated with the combination of cisplatin with radiation, compared with the group treated with radiation alone. Fractionated IR resulted in a significant increase in p21 expression, which was further enhanced when combined with cisplatin. Furthermore, treatment with cisplatin and fractionated IR resulted in a significant elevation of the expression of the autophagy-related genes, PI3KIII, Beclin1 and DRAM1. However, the levels of p-AKT were observed to decline following exposure to fractionated IR in the presence or absence of cisplatin. As for the apoptosis signaling genes, the combination of cisplatin and fractionated IR therapy resulted in a significant decrease in Bcl-2 expression and a marked upregulation of p21 expression. The current study offers strong evidence that the combination of cisplatin with radiation strengthens the killing effect of radiation via pro-apoptotic and pro-autophagic cell death. [ABSTRACT FROM AUTHOR]