Model oceny przydatności do rekultywacji terenu kopalń węgla kamiennego w północnym podnóżu góry Tianshan, Xinjiang

The ecological environment is significantly vulnerable to coal-mining activities in western China due to the cold and arid climate. The evaluation of land reclamation is therefore a key process that has to be known for the sustainable use of coal resources. A Bayes discriminant analysis method to evaluate the suitability level of land reclamation for coal mine lands in cold and arid regions of western China is presented. Ten factors influencing the suitability of land reclamation were selected as discriminant indexes in the suitability analysis. The data of eighty-four land reclamation units from sixteen coal-mining areas was used as training samples to develop a discriminant analysis model to evaluate the suitability level of land reclamation. The results show that the discriminant analysis model has high precision and the misdiscriminant ratio is 0.02 in the resubstitution process. The suitability levels of land reclamation for eleven sites in two coal mine lands were evaluated by using the model and the evaluation results are identical with that of the practical situation. Our method and findings are significant for decision makers in similar regions who want to prepare for possible strategies for land reclamation in the future.Środowisko ekologiczne jest bardzo wrażliwe na działalność wydobywczą węgla w zachodnich Chinach z powodu zimnego i suchego klimatu. Ocena rekultywacji gruntów jest zatem kluczowym procesem, który powinien być znany dla zrównoważonego wykorzystania zasobów węgla. W artykule przedstawiono metodę analizy dyskryminacyjnej Bayesa do oceny stopnia jej przydatności w rekultywacji gruntów kopalni węgla w zimnych i suchych regionach zachodnich Chin. Jako wskaźniki dyskryminacyjne w analizie przydatności wybrano dziesięć czynników wpływających na przydatność rekultywacji terenu. Dane z osiemdziesięciu czterech jednostek melioracyjnych z szesnastu obszarów górniczych wykorzystano jako próbki szkoleniowe do opracowania modelu analizy dyskryminacyjnej w celu oceny stopnia przydatności do rekultywacji terenu. Wyniki pokazują, że model analizy dyskryminacyjnej jest wysoko precyzyjny, a współczynnik błędnej dyskryminacji wynosi 0,02 w procesie resubstytucji. Poziomy przydatności rekultywacji dla jedenastu miejsc na dwóch terenach kopalni węgla zostały ocenione za pomocą modelu, a wyniki oceny są identyczne jak w praktyce. Model BDA ma wysoką precyzję i może być stosowany w praktyce inżynierskiej. W porównaniu z innymi metodami predykcji model BDA ma stabilną strukturę, a proces dyskryminacyjny jest prosty i wygodny. Jest to wstępna próba zastosowania teorii analizy dyskryminacyjnej Bayesa do oceny poziomu jej przydatności w rekultywacji gruntów, w szczególności w zachodnich Chinach, dla obszarów kopalń węgla. Wypracowana metoda i wyniki są istotne dla decydentów w podobnych regionach, którzy chcą przygotować się do możliwych strategii rekultywacji gruntów w przyszłości

The Trend of Permeability of Loess in Yili, China, under Freeze–Thaw Cycles and Its Microscopic Mechanism

Loess landslides induced by the freeze–thaw effect frequently occur in Yili, China. Freeze–thaw cycles cause indelible changes in the soil microstructure, affecting its permeability. This study investigated the impacts of freeze–thaw cycles on the permeability of Yili loess using permeability tests on undisturbed (virgin, in situ) and remolded loess samples taken before and after freeze–thaw cycles. Scanning electron microscopy and nuclear magnetic resonance techniques were utilized to investigate the microscopic mechanism of the freeze–thaw process on the loess. Grey relation analysis (GRA) was employed to analyze the correlation between macroscopic permeability and microscopic parameters (maxi. radius, eccentricity, fractal dimension, directional probability entropy, and porosity). The results revealed that the permeability and all the microstructure parameters have roughly shown the same trend: “fluctuation–towards equilibrium–stability”. Firstly, the permeability coefficients of original and remolded loess experienced three and two peaked–trends, respectively, before 30 freeze–thaw cycles. The trends eventually stabilized within 30–60 freeze–thaw cycles. Increased number of freeze–thaw cycles disintegrated large particles in undisturbed loess into medium–sized particles, and particle shapes became more uncomplicated. Medium–sized particles in the remolded loess agglomerated to larger particles with more complex shapes. Furthermore, the overall porosity of the originally undisturbed loess decreased, and large and medium–sized pores transformed into small pores and micropores. In contrast, the overall porosity of remolded loess increased. Finally, the results revealed that permeability coefficients of the undisturbed and remolded loess became closely related with eccentricity and porosity, respectively. This study provides a reference for preventing and governing the loess landslides induced by the freeze–thaw cycles and permeability reduction in construction on loess in seasonally frozen areas in Yili

Investigation of Changes to Triaxial Shear Strength Parameters and Microstructure of Yili Loess with Drying–Wetting Cycles

This research examined the drying–wetting cycles induced changes in undrained triaxial shear strength parameters and microstructural changes of Yili loess. The drying–wetting cycles were selected as 0, 1, 3, 5, 10, 20 and 30. Then, we collected Yili loess samples and performed unconsolidated-undrained (U-U) triaxial shearing tests to ascertain the variation in shear strength parameters with drying–wetting cycles. Additionally, we investigated the microstructural changes of Yili loess samples under drying–wetting cycles simultaneously via nuclear magnetic resonance (NMR) and scanning electron electroscopy (SEM). Finally, we established a grey correlation model between shear strength and microstructural parameters. Under U-U conditions, the prime finding was that the loess’s shear strength parameters changed overall after drying–wetting cycles; in particular, the internal friction angle φ dropped significantly while the cohesion c changed only slightly during cycles. For all the cycles, the first cycle gave the highest change. Soil morphology deterioration was evident at the initial stage of cycles. During the entire drying–wetting cyclic process, pore size distribution showed progressive variance from two-peak to a single-peak pattern, while both porosity and the fractal dimension of pores increased gradually towards stability. Soil particle morphology became slowly simple and reached the equilibrium state after 20 drying–wetting cycles. Under cyclic drying–wetting stress, the shear strength parameter changes were significantly correlated to microstructural modifications. This investigation was related to loess in the westerly region. The findings were expected to provide new insight into establishment of the connection between microstructure and macro stress–strain state of loess. To some extent, it provided a theoretical basis for the prevention and control of loess engineering geological disasters in Yili, Xinjiang and other areas with similar climate and soil types

Discovery of Fluorescence Polarization Probe for the ELISA-Based Antagonist Screening of α₁‑Adrenergic Receptors

High-throughput screening (HTS) of ligand library to find new active molecules for G protein-coupled receptors is still a major interest, as well as an actual challenge. Fluorescence polarization (FP) assay portrays an essential role in HTS; however, in many cases, it was restricted by the absence of FP probes, the narrow measurement window, and low signal-to-noise (S/N) ratio. Herein, based on the modification of our previous probe <b>1</b> (QFL), we discovered an FP probe <b>3</b> (QGGFL) for α₁-adrenergic receptors (α₁-ARs), which has satisfactory fluorescence intensity, specific binding ability to receptors, and suitable fluorescence properties that were compatible with the filters in the FP system. Meanwhile, an “ELISA-like” strategy was designed for FP-based HTS assay in which proteins were adhered into a solid phase to improve the measurement window and S/N ratio. With fluorescent antagonist QGGFL and the ELISA strategy, we succeeded in establishing the first competitive binding FP assay for α₁-AR antagonists as the alternative of the radioligand binding assay

Low-Temperature, Bottom-Up Synthesis of Graphene via a Radical-Coupling Reaction

In this article, we demonstrated a method to synthesize graphene films at low temperature via a mild radical-coupling reaction. During the deposition process, with the effectively breaking of the C–Br bonds of hexabromobenzene (HBB) precursors, the generated HBB radicals couple efficiently to form graphene films at the low temperature of 220–250 °C. In situ low-temperature scanning tunneling microscopy was used to provide atomic scale investigation of the graphene growth mechanism using HBB as precursor. The chemical structure evolution during the graphene growth process was further corroborated by in situ X-ray photoelectron spectroscopy measurements. The charge carrier mobility of the graphene film grown at low temperature is at 1000–4200 cm² V^–1s^–1, as evaluated in a field-effect transistor device configuration on SiO₂ substrates, indicating the high quality of the films

COQ8B nephropathy: Early detection and optimal treatment

Abstract Background Mutations in COQ8B (*615567) as a defect of coenzyme Q10 (CoQ10) cause steroid resistant nephrotic syndrome (SRNS). Methods To define the clinical course and prognosis of COQ8B nephropathy, we retrospectively assessed the genotype and phenotype in patients with COQ8B mutations from Chinese Children Genetic Kidney Disease Database. We performed the comparing study of renal outcome following CoQ10 treatment and renal transplantation between early genetic detection and delayed genetic detection group. Results We identified 20 (5.8%) patients with biallelic mutations of COQ8B screening for patients with SRNS, non‐nephrotic proteinuria, or chronic kidney disease (CKD) of unknown origin. Patients with COQ8B mutations showed a largely renal‐limited phenotype presenting with proteinuria and/or advanced CKD at the time of diagnosis. Renal biopsy uniformly showed focal segmental glomerulosclerosis. Proteinuria was decreased, whereas the renal function was preserved in five patients following CoQ10 administration combined with angiotensin‐converting enzyme (ACE) inhibitor. The renal survival analysis disclosed a significantly better outcome in early genetic detection group than in delayed genetic detection group (Kaplan–Meier plot and log rank test, p = .037). Seven patients underwent deceased donor renal transplantation without recurrence of proteinuria or graft failure. Blood pressure showed decreased significantly during 6 to 12 months post transplantation. Conclusions COQ8B mutations are one of the most common causes of adolescent‐onset proteinuria and/or CKD of unknown etiology in the Chinese children. Early detection of COQ8B nephropathy following CoQ10 supplementation combined with ACE inhibitor could slow the progression of renal dysfunction. Renal transplantation in patients with COQ8B nephropathy showed no recurrence of proteinuria

cybLuc: An Effective Aminoluciferin Derivative for Deep Bioluminescence Imaging

To enhance the efficiency of firefly luciferase/luciferin bioluminescence imaging, a series of <i>N</i>-cycloalkylaminoluciferins (cyaLucs) were developed by introducing lipophilic N-cycloalkylated substitutions. The experimental results demonstrate that these cyaLucs are effective substrates for native firefly luciferase (Fluc) and can produce elevated bioluminescent signals in vitro, in cellulo, and in vivo. It should be noted that, in animal studies, <i>N</i>-cyclobutylaminoluciferin (cybLuc) at 10 μM (0.1 mL), which is 0.01% of the standard dose of d-luciferin (dLuc) used in mouse imaging, can radiate 20-fold more bioluminescent light than d-luciferin (dLuc) or aminoluciferin (aLuc) at the same concentration. Longer in vivo emission imaging using cybLuc suggests that it can be used for long-time observation. Regarding the mechanism of cybLuc, our cocrystal structure data from firefly luciferase with oxidized cybLuc suggested that oxidized cybLuc fits into the same pocket as oxyluciferin. Most interestingly, our results demonstrate that the sensitivity of cybLuc in brain tumor imaging contributes to its extended application in deep tissues