Properties of Crushed Red-Bed Soft Rock Mixtures Used in Subgrade

Slaking red-bed soft rocks are widely distributed in the south of Anhui Province, China, and several highways will go through this area. It is important to evaluate their physical and mechanical characteristics for the purpose of using this kind of soft rocks as materials for road construction. In this paper, the compacting tests, the resilient modulus tests, the California bearing ratio (CBR) tests, and permeability tests have been carried out on crushed red-bed soft rock mixtures. The test results showed that, for a given degree of compaction, the resilient modulus decreases linearly with the increase of moisture content. For a given moisture content, the resilient modulus and CBR values increase linearly with the increase of compaction degree, while the soaking swelling, water absorption capacity, and permeability coefficient decrease linearly. In other words, the strength and water stability are enhanced with the increase of the degree of compaction. The results demonstrate that the crushed red-bed soft rock mixtures can be directly used as materials for the highway construction by taking corresponding measures

Construction of Shanghai Diabetes Clinical Database and real-world study

Objective·To construct a clinical database of diabetes in Shanghai, mine the value of clinical data, and carry out real-world study.Methods·The data were extracted from Shanghai Link Healthcare Database. All original clinical data have undergone standard processes such as desensitization, encryption, cleaning, standardization, information extraction and structuring, and clinical data were analyzed by the method of medical statistics or machine learning according to different research contents.Results·The database has imported the clinical data of 150 million visits and treatment records of 2.12 million diabetic patients in 37 municipal hospitals over a ten-year period from 2013 to 2022. The overall analysis showed the basic characteristics and development trends of all aspects of diabetes disease in real-world settings, the potential risks of diabetes are discovered by constructing retrospective cohort, and the inherent patterns of the disease are revealed by using machine learning methods such as cluster analysis and network analysis.Conclusion·The establishment of Shanghai Diabetes Clinical Database can not only summarize and show the clinical status of diabetes, but also obtain more scientific achievements with realistic clinical value by real-world clinical data study

Association between systemic lupus erythematosus and inflammatory bowel disease in European and East Asian populations: a two-sample Mendelian randomization study

BackgroundPrevious studies have shown a coexistence phenomenon between systemic lupus erythematosus (SLE) and inflammatory bowel disease (IBD), but the causal relationship between them is still unclear. Therefore, we conducted a two-sample Mendelian randomization (MR) analysis using publicly available summary statistics data to evaluate whether there was a causal relationship between the two diseases.MethodsSummary statistics for SLE and IBD were downloaded from the Open Genome-Wide Association Study and the International Inflammatory Bowel Disease Genetics Consortium. European and East Asian populations were included in this MR work. We adopted a series of methods to select instrumental variables that are closely related to SLE and IBD. To make the conclusion more reliable, we applied a variety of different analysis methods, among which the inverse variance–weighted (IVW) method was the main method. In addition, heterogeneity, pleiotropy, and sensitivity were assessed to make the conclusions more convincing.ResultsIn the European population, a negative causal relationship was observed between SLE and overall IBD (OR = 0.94; 95% CI = 0.90, 0.98; P < 0.004) and ulcerative colitis (UC) (OR = 0.93; 95% CI = 0.88, 0.98; P = 0.006). After removing outliers with Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), the results remained consistent with IVW. However, there was no causal relationship between SLE and Crohn’s disease. In the East Asian population, no causal relationship was found between SLE and IBD.ConclusionOur results found that genetic susceptibility to SLE was associated with lower overall IBD risk and UC risk in European populations. In contrast, no association between SLE and IBD was found in East Asian populations. This work might enrich the previous research results, and it may provide some references for research in the future

Disturbance effect analysis of pipe jacking construction based on failure approach index

In order to evaluate the influence of pipe jacking construction process on ground subsidence and surrounding buildings, the numerical simulation of the construction process was carried out by FLAC3D, and the failure approach index (FAI) of the rock and soil around the pipeline was calculated to describe quantitatively their risk and damage state. The numerical results show that the final settlements of the buildings around the pipeline are less than the buildings' safety control values. The rock or soil mass within 0.8 times of the pipe diameter are in the excavation damage zone and disturbance zone (0.8≤FAI≤1.3), while outside 0.8 times of the pipe diameter are basically undisturbed (FAI≤0.8)

New mimarachnids (Hemiptera, Fulgoromorpha, Fulgoroidea) in mid-Cretaceous Burmese amber

A new genus and species, Multistria orthotropa gen. et sp. nov., and a new species, Dachibangus hui sp. nov., of Mimarachnidae are described from the mid-Cretaceous Burmese amber. These new taxa display unique wing color patterns and extend the Mesozoic diversity of Mimarachnidae. The evolution of wing venation, phylogenetic placement of Mimarachnidae, and anti-predation defenses of this family in Burmese amber forest are briefly discussed

Pore characteristics and mechanical behaviors of autoclaved aerated concrete produced from coal bottom ash and tailings

Abstract The solid wastes such as coal bottom ash and tailings are currently widely used in various building materials, but further research on their application in autoclaved aerated concrete (AAC) is needed. To study the physical and mechanical properties of AAC produced from coal bottom ash and tailings, the pore characteristics of two different density grades of AAC were extracted and analyzed, and wave velocity and uniaxial compressive tests under water‐saturated and dry conditions were carried out. The results show that the AAC produced from solid waste has excellent performance. The specimen is anisotropic, and the pore size distribution of its cross‐section is mainly concentrated in the ranges of <0.1, 0.1–0.5, and 0.5–1.0 mm. The pore size perpendicular to the direction of rise is smaller and the pores number is greater. The wave velocity and uniaxial compressive strength of the test specimens in the water‐saturated state are significantly lower than those in the dry state. The strengths of specimens loaded perpendicular to the direction of rise are higher than those loaded parallel to the direction of rise whether water‐saturated or dry. The failure mode of the water‐saturated specimens are different from those of dry specimens, which is manifested in the act that there are fewer surface cracks when the specimens fail in the water‐saturated state, while there are more surface cracks in the dry specimens, and their morphology is irregular. The physicochemical effect between water and components and the mechanical effect of pore water are the reasons for the deterioration of AAC's mechanical properties. The results help to reveal the performance of AAC produced from solid waste and have good practical significance

Progresses on the intelligent construction and operation maintenance of urban under-lake tunnels

China is currently at an important stage of urbanization. In recent years, the number and scale of under-lake tunnels in southern cities of China are growing consistently, which brings opportunities and challenges in intelligent construction and operation maintenance. Due to the long length of the under-lake tunnel, the large volume of concrete to be cast, the complex environment of the buried section and the underground environment of the lake bottom, the hydration heat and stress crack have been the main challenges of the under-lake tunnel engineering in crack control and waterproofing aspect. Simultaneously, with the development of big data, intelligent construction, information technology, and other techniques, these techniques are gradually applied to the whole life cycle of tunnel engineering including survey, design, construction, operation, and maintenance. The construction of the lake tunnel project is setting off a new round of technological innovation. This paper systematically summarizes the technical breakthroughs and application of technologies such as intelligent construction and information technology in the construction of under-lake tunnels in China, and puts forward reasonable suggestions on the key technologies of intelligent construction and operation maintenance for urban under-lake tunnel engineering

Experimental investigation on the deterioration of the physical and mechanical properties of autoclaved aerated concrete at elevated temperatures

Autoclaved aerated concrete (AAC) has been extensively studied and applied in the past decades because of its excellent thermal insulation and acoustic performance, energy efficiency, and outstanding structural performance. To investigate the deterioration characteristics of AAC under high temperatures, the physico-mechanical properties of AAC at different temperatures were tested by mass loss, wave velocity, and compressive tests, and the deterioration mechanism was discussed by X-ray diffraction (XRD), thermogravimetric analysis (TGA), and scanning electron microscopy (SEM) tests. The results showed that after exposure to elevated temperatures, the parameters of apparent form, mass loss, wave velocity, and compressive strength underwent remarkable conversions. It was observed that the ultrasonic behavior of AAC was affected at high temperatures as it increased at 100°C and decreased beyond 100°C. In addition, the compressive strength exhibited a two-stage transformation, slightly increased from ambient temperature to 300°C, and exhibited a rapid reduction beyond 300°C. At 900°C, the specimen lost its strength. By XRD, TGA, and SEM, it was confirmed that a series of physicochemical changes in AAC, such as the water escape and evaporation, decomposition of calcium silicate hydrate and calcium carbonate, and structural damage, were the primary reasons for the deterioration of the physical and mechanical properties at elevated temperatures

The self-assembly of CaCO3 crystals in the presence of protein

Calcium carbonate/bovine serum albumin (CaCO3/BSA) hybrid crystals with flying-plate shape have been successfully synthesized at ambient temperature. The products have been characterized by X-ray powder diffraction (XRD), HRTEM-SAED, EDS, field-emission scanning electron microscope (FE-SEM), thermogravimetry-differential thermal analyses (TG-DTA), FT-IR, photoluminescence (PL) and circular dichroism (CD) spectroscopy. The results of the research showed that the as-prepared CaCO3/BSA hybrid crystals with sizes about 1 μm in diameter were self-assembled by nanoparticles. Furthermore, the interactions between CaCO3 and BSA were studied at supramolecular level and an interesting mechanism about the formation of the CaCO3/BSA hybrid crystals was discussed. © 2009 Elsevier B.V. All rights reserved