Experimental Study on Enhancing the Mechanical Properties of Sandy Soil by Combining Microbial Mineralization Technology with Silty Soil.

Currently, coastal sandy soils face issues such as insufficient foundation strength, which has become one of the crucial factors constraining urban development. Geotechnical engineering, as a traditional discipline, breaks down disciplinary barriers, promotes interdisciplinary integration, and realizes the green ecological and low-carbon development of geotechnical engineering, which is highly important. Based on the "dual carbon" concept advocating a green and environmentally friendly lifestyle, Bacillus spores were utilized to induce calcium carbonate precipitation technology (MICP) to solidify coastal sandy soils, leveraging the rough-surface and low-permeability characteristics of silty soil. The mechanical-strength variations in the samples were explored through experiments, such as calcium carbonate generation rate tests, non-consolidated undrained triaxial shear tests, and scanning electron microscopy (SEM) experiments, to investigate the MICP solidification mechanism. The results indicate that by incorporating silty soil into sandy soil for MICP solidification, the calcium carbonate generation rates of the samples were significantly increased. With the increase in the silty-soil content, the enhancement range was 0.58-3.62%, with the maximum calcium carbonate generation rate occurring at a 5% content level. As the silty-soil content gradually increased from 1% to 5%, the peak deviator stress increased by 4.2-43.2%, enhancing the sample shear strength. Furthermore, the relationship between the internal-friction angle, cohesion, and shear strength further validates the enhancement of the shear strength. Silty soil plays roles in adsorption and physical filling during the MICP solidification process, reducing the inter-particle pores in sandy soil, increasing the compactness, providing adsorption sites, and enhancing the calcium carbonate generation rate, thereby improving the shear strength. The research findings can provide guidance for reinforcing poor coastal sandy-soil foundations in various regions.

A meta-analysis on diagnostic accuracy of spot urinary protein to creatinine ratio versus 12-h proteinuria in preeclampsia.

To systematically review the diagnostic accuracy of spot urinary protein to creatinine ratio (PCR) and 12-h proteinuria in preeclampsia and to estimate which is a preferred alternative method for 24-h proteinuria, we carried out this meta-analysis. 25 primary studies were included based on searching strategy. For spot urinary PCR, our results showed pooled sensitivity of 87% (95% confidence interval [CI] 83%-91%) and specificity of 86% (95% CI 79%-91%), with an area under curve (AUC) of 0.93 (0.90-0.95). For 12-h proteinuria, pooled sensitivity and specificity were 92% (95% CI 87%-96%) and 99% (95% CI 75%-100%), respectively, with an AUC of 0.97 (0.95-0.98). Fagan plot and likelihood ratio scattergram showed that 12-h proteinuria yielded a better discriminatory performance on diagnosis of proteinuria (≥0.3 g/24 h). These results indicated that 12-h proteinuria estimation shows better clinical value than spot urine PCR for diagnosis of preeclampsia. However, due to the severity of condition and the fact that preeclampsia patients cannot wait for 12 h, spot urine PCR can be used as one of the diagnostic indicators.

Molecular modification effects on the electrochromic and photochromic properties of diarylethene with intramolecular isomerization behavior.

Diarylethene (DAE) is one of the most widely used functional units for electrochromic or photochromic materials. To better understand the molecular modification effects on the electrochromic and photochromic properties of DAE, two modification strategies, substitution with functional groups or heteroatoms, were investigated theoretically by density functional theory calculations. It is found that red-shifted absorption spectra caused by a decreased highest occupied molecular orbital-lowest unoccupied molecular orbital energy gap and S0 → S1 transition energy during the ring-closing reaction become more significant by adding different functional substituents. In addition, for two isomers, the energy gap and S0 → S1 transition energy decreased by heteroatom substitution of S atoms with O or NH, while they increased by replacing two S atoms with CH2. For intramolecular isomerization, one-electron excitation is the most effective way to trigger the closed-ring (O → C) reaction, while the open-ring (C → O) reaction occurs most readily in the presence of one-electron reduction. Moreover, it is confirmed that substitution with strong electron donating groups (-OCH3/-NH2) or with one O/two CH2 heteroatoms leads to a more favorable closed-ring (O → C) reaction. Functionalized with strong electron-withdrawing groups (-NO2 and -COOH) or one/two NH heteroatom substitutions, the open-ring (C → O) reaction is easier. Our results confirmed that the photochromic and electrochromic properties of DAE can be tuned effectively by molecular modifications, which provides theoretical guidance for the design of new DAE-based photochromic/electrochromic materials.

Electronic structure evolution induced by the charge redistribution during the construction of two-dimensional polymer networks from monomers to crystal frameworks.

Two-dimensional covalent organic frameworks (COFs) are a new type of porous crystalline material constructed by the linkage of organic building units through covalent bonds to produce predetermined structures. Here, the electronic structure evolution induced by the charge redistribution during the construction of two-dimensional polymer networks (sp2c-COF-2 and COF-66) from building units to crystal frameworks is examined theoretically. The calculated results demonstrate that the electronic structure of the framework is controlled by the relative energy level between the frontier orbitals of organic building core and linker units as well as the charge transfer amount between them during the construction of the framework. Moreover, it is observed that a noncoplanar framework becomes more conjugated because the charge transfer amount between core and linker units becomes larger during the construction of 2D frameworks, which leads to a larger charge carrier mobility within the 2D structure of COFs. The charge carrier mobility along the z-direction of the COF crystal is dominated by the interface interaction between COF layers. Thereby, we believed reasonable design or selection of organic building units plays a key role in improving the electronic and optoelectronic properties of such 2D organic frameworks.

Improving the chemical stability of blue heteroleptic iridium emitter FIrpic in the lowest triplet state through ancillary ligand modification: a theoretical perspective.

With the aim of providing a deeper understanding of the underlying degradation mechanisms associated with the lifetime of blue emitters during the decay process of blue PhOLEDs, quantum chemistry studies were performed to examine the chemical degradation mechanism of common sky blue emitter iridium(III)bis(4,6-di-fluorophenyl)-pyridinato-N,C2')picolinate (FIrpic) and its derivatives with density functional theory (DFT) calculations. For these Ir(III) emitters, the Ir-N1 bond between the ancillary ligand (picolinate) and central iridium will be broken by external light stimuli, which is followed by conversion from the initial emissive metal-to-ligand charge transfer (3MLCT) state to the non-emissive metal centered (3MC) state. The potential energy change for the photo-induced degradation path is then dominated by the energy levels of the 3MT and 3MC states, which are related to the triplet transition energy and the Ir-N1 bond strength, respectively. Thereby, the Ir-N1 bond dissociation in the lowest triplet state will be much harder to proceed if the S0 → T1 transition energy gets more energetically stable or the bond strength gets larger. It is believed that strategic modification of the ancillary ligand, especially by substitution of electron-donating groups at the para position of the pyridyl N atom or extension of the p-electron delocalization, is an effective and easy way to enhance the photochemical stability of the typical blue emitter FIrpic.

Gastrodin inhibits high glucose-induced inflammation, oxidative stress and apoptosis in podocytes by activating the AMPK/Nrf2 signaling pathway.

Diabetic nephropathy (DN) is a serious and common complication of type 1 and 2 diabetes. Gastrodin has been reported to suppress high glucose (HG)-induced inflammation and oxidative stress in vivo and in vitro. However, the effect of gastrodin on DN has not been fully elucidated. The present study aimed to investigate the underlying mechanism involved in the effect of gastrodin on podocyte injury caused by DN. Cell viability was evaluated using Cell Counting Kit-8 assay and secretion levels of TNF-α, IL-1ß and IL-6 were measured using ELISA. The levels of malondialdehyde, activities of lactate dehydrogenase and superoxide dismutase were quantified using corresponding assay kits. Additionally, cell apoptosis was analyzed by TUNEL assay, whilst protein expressions related to inflammation, apoptosis and the 5'-AMP-activated protein kinase (AMPK)/nuclear factor erythroid 2-related factor 2 (Nrf2) signaling pathway were measured by western blot analysis. The results showed that gastrodin increased the viability of MPC5 cells following HG stimulation. Gastrodin also alleviated HG-induced inflammation, oxidative stress and apoptosis in MPC5 cells. Furthermore, gastrodin promoted activation of the AMPK/Nrf2 pathway in MPC5 cells. Treatment with the AMPK inhibitor, compound C, reversed the inhibitory effects of gastrodin on inflammation, oxidative stress and cell apoptosis. To conclude, treatment of MPC5 cells with gastrodin can attenuate HG-induced inflammation, oxidative stress and cell apoptosis by activating the AMPK/Nrf2 signaling pathway. Results from the current study suggest that gastrodin can be used as an effective therapeutic agent against HG-induced podocyte injury in DN.

Diagnostic performance of initial blood urea nitrogen combined with D-dimer levels for predicting in-hospital mortality in COVID-19 patients.

The crude mortality rate in critical pneumonia cases with coronavirus disease 2019 (COVID-19) reaches 49%. This study aimed to test whether levels of blood urea nitrogen (BUN) in combination with D-dimer were predictors of in-hospital mortality in COVID-19 patients. The clinical characteristics of 305 COVID-19 patients were analysed and were compared between the survivor and non-survivor groups. Of the 305 patients, 85 (27.9%) died and 220 (72.1%) were discharged from hospital. Compared with discharged cases, non-survivor cases were older and their BUN and D-dimer levels were significantly higher (P < 0.0001). Least absolute shrinkage and selection operator (LASSO) and multivariable Cox regression analyses identified BUN and D-dimer levels as independent risk factors for poor prognosis. Kaplan-Meier analysis showed that elevated levels of BUN and D-dimer were associated with increased mortality (log-rank, P < 0.0001). The area under the curve for BUN combined with D-dimer was 0.94 (95% CI 0.90-0.97), with a sensitivity of 85% and specificity of 91%. Based on BUN and D-dimer levels on admission, a nomogram model was developed that showed good discrimination, with a concordance index of 0.94. Together, initial BUN and D-dimer levels were associated with mortality in COVID-19 patients. The combination of BUN ≥ 4.6 mmol/L and D-dimer ≥ 0.845 µg/mL appears to identify patients at high risk of in-hospital mortality, therefore it may prove to be a powerful risk assessment tool for severe COVID-19 patients.

Coronavirus disease 2019 (COVID-19) pneumonia in a hemodialysis patient: A case report.

RATIONALE: The 2019 novel coronavirus disease (COVID-19) causes a novel, atypical pneumonia that has brought huge public health challenges across the globe. There is limited data about patients with end-stage renal disease who also suffer from COVID-19. In this report, we discuss the case of a hemodialysis patient who developed COVID-19 pneumonia in the clinical course. PATIENT CONCERNS: A 79-year-old man who had end-stage renal disease (ESRD) and was taking regular hemodialysis was admitted to hospital for a fever and dry cough. The patient, who also had cardiovascular disease, had no history of contact with COVID-2019 patients. DIAGNOSIS: The patient was diagnosed with COVID-2019 by the reverse-transcriptase polymerase chain reaction (RT-PCR), and his pharyngeal swab for SARS-CoV-2 was positive. INTERVENTION: The treatment was mainly supportive and the patient was intensively monitored. He was treated with oxygen, broad-spectrum antibiotics, antiviral drugs, and methylprednisolone. The patient took continuous renal replacement therapy (CRRT) every 2 days. OUTCOMES: After 19 days, an RT-PCR assay for SARS-CoV-2 was negative, and computed tomography (CT) of the patient's thorax indicated that the pulmonary inflammatory exudation was absorbed and pulmonary infection improved significantly. He was discharged on day 29 after recovering from COVID-2019 pneumonia. LESSONS: The courses of disease and treatment options for this individual were significantly more complicated than those for ordinary patients. Therefore, it was necessary to monitor the condition of the patient closely and to protect the dialysis unit staff from being infected. Compared with other severe COVID-2019 cases, this patient recovered more quickly following treatment, which was likely due to the removal of inflammatory mediators by CRRT. This implies that blood purification might be an important option for hemodialysis patients with COVID-19.