Single-nucleus analysis reveals microenvironment-specific neuron and glial cell enrichment in Alzheimer's disease.

BACKGROUND: Alzheimer's disease (AD) is a complicated neurodegenerative disease. Neuron-glial cell interactions are an important but not fully understood process in the progression of AD. We used bioinformatic methods to analyze single-nucleus RNA sequencing (snRNA-seq) data to investigate the cellular and molecular biological processes of AD. METHOD: snRNA-seq data were downloaded from Gene Expression Omnibus (GEO) datasets and reprocessed to identify 240,804 single nuclei from healthy controls and patients with AD. The cellular composition of AD was further explored using Uniform Manifold Approximation and Projection (UMAP). Enrichment analysis for the functions of the DEGs was conducted and cell development trajectory analyses were used to reveal underlying cell fate decisions. iTALK was performed to identify ligand-receptor pairs among various cell types in the pathological ecological microenvironment of AD. RESULTS: Six cell types and multiple subclusters were identified based on the snRNA-seq data. A subcluster of neuron and glial cells co-expressing lncRNA-SNHG14, myocardin-related transcription factor A (MRTFA), and MRTFB was found to be more abundant in the AD group. This subcluster was enriched in mitogen-activated protein kinase (MAPK)-, immune-, and apoptosis-related pathways. Through molecular docking, we found that lncRNA-SNHG14 may bind MRTFA and MRTFB, resulting in an interaction between neurons and glial cells. CONCLUSIONS: The findings of this study describe a regulatory relationship between lncRNA-SNHG14, MRTFA, and MRTFB in the six main cell types of AD. This relationship may contribute to microenvironment remodeling in AD and provide a theoretical basis for a more in-depth analysis of AD.

Cytotoxic Tirucallane and Apotirucallane Triterpenoids from the Stems of Picrasma quassioides.

Phytochemical investigation on the stems of Picrasma quassioides led to the isolation of a novel compound, picraquassin A (1), with an unprecedented 21,24-cycloapotirucallane skeleton, and four new apotirucallane-type triterpenoids (2-5), together with 15 new tirucallane-type triterpenoids (6-20) and 10 known tirucallane-type triterpenoids (21-30). To our knowledge, this is the first report demonstrating the presence of apotirucallane-type triterpenoids in the genus Picrasma. The structures of the new compounds were determined based on spectroscopic data interpretation. Cytotoxicities of the isolated compounds were evaluated using three human cancer cell lines, MKN-28, A-549, and MCF-7. Compound 2 exhibited the most potent activity against MKN-28 cells with an IC50 value of 2.5 µM. Flow cytometry and Western blot analysis revealed that 2 induces the apoptosis of MKN-28 cells via activating caspase-3/-9, while increasing Bax and Bad and decreasing Bcl-2 expression levels.

A novel utilization of raw sepiolite: preparation of magnetic adsorbent directly based on sol-gel for adsorption of Pb(II).

The constraints of industrial separation technology for low grade sepiolite greatly limit the development and utilization of these potential resources. In this work, a novel sepiolite adsorbent loaded with copper ferrite was prepared by sol-gel method to remove Pb(II) from wastewater. The effects of various factors on Pb(II) removal ratio were investigated. The maximum adsorption capacities at 293, 313, and 333 K were 1285.32, 1325.45, and 1390.54 mg/g, respectively. The adsorption of Pb(II) by magnetic sepiolite was a spontaneous endothermic process. Besides, the adsorption process followed Langmuir isothermal adsorption model and pseudo-second-order kinetic model. The main adsorption mechanism of Pb(II) removal was electrostatic attraction, ion exchange, and surface complexation. The improvement of Pb(II) absorption indicated that the efficient removal of Pb(II) can be realized by phosphate groups introduced in the preparation process and the carbonate groups contained in gangue minerals.

Enhancement of leaching copper by organic agents from waste printed circuit boards in a sulfuric acid solution.

Leaching copper from waste printed circuit boards (WPCBs) by hydrometallurgy has always been a hot research topic. At atmospheric pressure, hydrogen peroxide (H2O2) was used as an oxidant to study the leaching behavior of copper from WPCBs in sulfuric acid (H2SO4) solution with ethylene glycol (EG). To elucidate the leaching mechanism of copper from WPCBs, the effect of various parameters on the leaching performance with or without EG was investigated. The results showed that the copper leaching process from WPCBs in the presence of EG was found to conform to the ash diffusion-controlled shrinking core model according to the kinetic curve and a activation energy of 18.38 kJ/mol. Moreover, the presence of EG strengthened the stability of H2O2, improved dispersity and increased electrical activity of WPCBs, which enhanced the leaching of copper from WPCBs in the high leaching temperature (>323.15 K). As a result, apart from the fact that the optimal leaching concentration of H2O2 was reduced by the addition of EG, the improved copper leaching efficiency from WPCBs was achieved by the addition of EG, as demonstrated by a maximum copper leaching efficiency of 98.01% and a maximum loss rate of 29.68%. Besides, the mineralogical and morphological properties of leaching residue validated the leaching results. Based on this, our findings confirmed the enhanced leaching performance of copper from WPCBs by EG, which benefited for the efficient recovery of copper from WPCBs.

Reverse flotation efficiency and mechanism of various collectors for recycling waste printed circuit boards.

Reverse flotation was used to recover metal components from waste printed circuit boards (PCBs). The micro-morphology and chemical composition analysis of raw materials indicated that waste PCBs are mainly composed of glass fibers, ceramics and valuable metals. The effects of collector dosage and temperature on flotation efficiency were investigated and evaluated. The flotation results using various collectors showed that the efficient recovery of metal components could be achieved via reverse flotation with the diesel oil (DO) dosage of 370-1110 g/t, composite collector (CC) dosage of 370-740 g/t and laurylamine (LAM) dosage of 740 g/t, respectively. The suitable temperature should be controlled at around 20 °C for these collectors. The results also indicated that the selectivity of DO for nonmetal particles was stronger than that of CC and LAM. In summary, reverse flotation is a feasible and environmental approach for disposal of waste PCBs.

Recovery of metallic concentrations from waste printed circuit boards via reverse floatation.

Efficient disposal of waste printed circuit boards (PCBs) is favorable toward recovering valuable components and reducing pollution. Reverse floatation was used to recover metallic concentrations from waste PCBs. Basic properties and mineralogical characteristics of raw PCBs were tested and analyzed. Results indicated that the grade of metallic concentrations declined as the size fraction of PCBs decreased. The major metallic elements found in PCBs were Cu, Pb, and Sn, as well as trace elements were also found in fine PCB particles. Kerosene and terpenic oil were used as the collector and frother in the floatation experiments. The effects of various operational factors, including the feeding concentration, aeration rate, and agitation speed of floatation machine, on the floatation performance of -0.25mm PCBs were experimentally studied to determine optimal range. The floatation results suggested that the yield of sinks and grade of metallic concentrations diminished significantly with the decrease of size fraction of PCBs. The maximum yields of sinks and highest grades of metallic concentrations were 48.72% and 16.86%, 47.96% and 14.61%, 44.36% and 8.81%, with the optimum recoveries of metallic concentrations of 94.69%, 90.06%, and 75.96% for size fractions of 0.125-0.25mm, 0.074-0.125mm, and -0.074mm PCBs, respectively. The recovery efficiency of metallic concentrations declined as the size fraction decreased. The efficient overall recovery performance of metallic concentrations from waste PCBs was obtained via reverse floatation. This study provides an alternative approach for disposing waste PCBs.

The secondary release of mercury in coal fly ash-based flue-gas mercury removal technology.

The secondary release of mercury from coal fly ash is a negative by-product from coal-fired power plants, and requires effective control to reduce environmental pollution. Analysing particle size distribution and composition of the coal fly ash produced by different mercury removing technologies indicates that the particles are generally less than 0.5 mm in size and are composed mainly of SiO2, Al2O3, and Fe2O3. The relationships between mercury concentration in the coal fly ash, its particle size, and loss of ignition were studied using different mercury removing approaches. The research indicates that the coal fly ash's mercury levels are significantly higher after injecting activated carbon or brominating activated carbon when compared to regular cooperating-pollution control technology. This is particularly true for particle size ranges of >0.125, 0.075-0.125, and 0.05-0.075 mm. Leaching experiments revealed the secondary release of mercury in discarded coal fly ash. The concentration of mercury in the coal fly ash increases as the quantity of injecting activated carbon or brominating activated carbon increases. The leached concentrations of mercury increase as the particle size of the coal fly ash increases. Therefore, the secondary release of mercury can be controlled by adding suitable activated carbon or brominating activated carbon when disposing of coal fly ash. Adding CaBr2 before coal combustion in the boiler also helps control the secondary release of mercury, by increasing the Hg(2+) concentration in the leachate. This work provides a theoretical foundation for controlling and removing mercury in coal fly ash disposal.

[Effects of thinning intensities on population regeneration of natural Quercus variabilis forest on the south slope of Qinling Mountains].

Taking the natural Quercus variabilis forest in Shangluo, south slope of Qinling Mountains as the object in May 2006 and August 2011, which was under close-to-natural management of different thinning intensities (30%, 20%, 10%), and the un-thinned forest as the control, changes of the stand growth situation before and after thinning, population regeneration, species diversity and soil fertility after 5 years of thinning were analyzed, and the effects of thinning on forestland revegetation and community development were evaluated comprehensively. The results showed that the number of 1-6 years old Q. variabilis seedlings increased with increasing thinning intensity, while no significant difference was found for above 6 years old seedlings. The regeneration potentials of population under 10%, 20% and 30% thinning were respectively increased by 10.8%, 28.5% and 32.9% compared with the control. Thinning promoted the DBH and crown of the trees and shrubs, as well as the height of shrubs, especially for light-loving plants, and the effect of promotion increased with increasing thinning intensity. The species diversity and soil fertility were improved after thinning, in order of 30% > 20% > 10% > control. The thinning intensity of 30% (canopy density 0.6) was more conducive to the continuable development of the natural Q. variabilis forest in which canopy density was above 0.85.

[Regeneration mode of Xanthoceras sorbifolia population and its contribution to population regeneration].

Sexual and asexual propagation of Xanthoceras sorbifolia natural populations in different habitats and their importance in population regeneration were studied. The results showed that X. sorbifolia populations were capable of the sexual and asexual propagation in 3 slope aspects, but a balance between the two propagation modes was observed. In sunny and semi-shady slope habitats, seedling amount and space-occupying competence were relatively high, suggesting that the sexual propagation was dominant. In semi-sunny slope habitat, the populations were superior in sexual sprout amount and space-occupying competence, suggesting that the predominant propagation mode was asexual. In the same habitats, asexual sprouts grew better than seedlings, while the growth of seedlings was in the order of sunny slope > semi-sunny slope > semi-shady slope on the basis of the same origin. The bottleneck stage appeared from seeds to seedlings for sexual propagation and from seedling to ramet for asexual propagation. X. sorbifolia invaded and settled in a way of sexual propagation in new habitats, and then rapidly occupied habitat space in a way of asexual propagation.

[Effects of thinning intensity on the seed bank and seedling growth of Quercus variabilis on the south slope of Qinling Mountains, Northwest China].

In August-November 2010 and August 2011, and taking the pure Quercus variabilis forests under close-to-natural management of different thinning intensity (30%, 20%, and 10%) in Shangluo district of south slope of Qinling Mountains as the object, an investigation was conducted on the seed amount of seed bank, the survival rate and growth status of seedlings, and their relationships with environmental factors 4-5 years after thinning. As compared with the control, the seed amount in the seed bank of 10%, 20%, and 30% thinning plots increased by 2.0%, 21.1%, and 34.8%, respectively in the fourth year after thinning, and the 1-year-old seedlings amount increased by 28.5%, 99.7%, and 122.2%, respectively in the next year. The survival rate of the seedlings in the 10%, 20%, and 30% thinning plots was increased by 25.5%, 235.7%, and 480.0%, respectively in the fifth year after thinning. Thinning improved the light, temperature, soil moisture, and soil nutrient conditions in the forests, which promoted the height- and new shoot growth and the leaf area index of each age seedlings. The three growth indices also increased with increasing thinning intensity. In the Q. variabilis forest with a canopy density of > or = 0.85, the thinning intensity 30% (canopy density 0.6) was most conducive to the seed germination and seedling growth.

[Effects of thinning intensity on Pinus tabulaeformis plantation in Huanglong Mountain, Northwest China: a comprehensive evaluation].

A sampling plot investigation was conducted on the seedling regeneration, stand growth, species diversity, and soil characteristics in a Pinus tabulaeformis plantation in Huanglong Mountain on the Loess Plateau of Northwest China after 7 years of close-to-natural management thinning 15% (light thinning), 30% (medium thinning), and 45% (heavy thinning), with the effect of different thinning intensities evaluated. With the increase of thinning intensity, the amount and growth indices of 1-7 years old P. tabulaeformis seedlings increased, but the mean annual increments of the growth indices decreased after an initial increase, with the maximum under medium thinning. As compared with the control (un-thinned plantation), the individual volume under light, medium, and heavy thinning was increased by 20.9%, 32.1% and 52.6%, the volume per hm2 decreased by 4.4%, 15.1%, and 25.3%, and the mean annual growth rate of volume increased by 28.6%, 46.2% and 82.0%, respectively. The species diversity and soil characteristics were improved under thinning, with the order of heavy thinning > medium thinning > light thinning > un-thinning. In this study, 45% thinning was most suitable to the management of P. tabulaeformis plantation in Huanglong Mountain.

[Effects of thinning intensity on community stability of Quercus liaotungensis forest on Loess Plateau].

A sampling plot investigation was conducted on the Quercus liaotungensis forests on Loess Plateau, China under close-to-natural management thinning 13.4% (light thinning) and 30.0% (heavy thinning). Taking the un-thinned forest as the control, the population regeneration, woodland productivity, soil fertility, and species diversity of the forests after 5 years of thinning were studied, with the community stability evaluated by calculating the subordinate function values based on fuzzy comprehensive evaluation. Comparing with the control, the regeneration potential of the forests after light and heavy thinning promoted by 14.2% and 20.2%, arbor volume reduced by 9.0% and 23.8%, shrub biomass increased by 7.3% and 12.2%, and herb biomass increased by 10.5% and 31.6%, respectively. In addition, the soil fertility and species diversity indices were higher in thinning forests than in the control. The community stability showed the order of heavy thinning forest > light thinning forest > un-thinned forest, suggesting that the close-to-natural management thinning 30.0% was more suitable to the management of secondary Q. liaotungensis forest on Loess Plateau.