Circular RNA vaccines against SARS-CoV-2 and emerging variants.

As the emerging variants of SARS-CoV-2 continue to drive the worldwide pandemic, there is a constant demand for vaccines that offer more effective and broad-spectrum protection. Here, we report a circular RNA (circRNA) vaccine that elicited potent neutralizing antibodies and T cell responses by expressing the trimeric RBD of the spike protein, providing robust protection against SARS-CoV-2 in both mice and rhesus macaques. Notably, the circRNA vaccine enabled higher and more durable antigen production than the 1mΨ-modified mRNA vaccine and elicited a higher proportion of neutralizing antibodies and distinct Th1-skewed immune responses. Importantly, we found that the circRNARBD-Omicron vaccine induced effective neutralizing antibodies against the Omicron but not the Delta variant. In contrast, the circRNARBD-Delta vaccine protected against both Delta and Omicron or functioned as a booster after two doses of either native- or Delta-specific vaccination, making it a favorable choice against the current variants of concern (VOCs) of SARS-CoV-2.

Unbiased interrogation of functional lysine residues in human proteome.

CRISPR screens have empowered the high-throughput dissection of gene functions; however, more explicit genetic elements, such as codons of amino acids, require thorough interrogation. Here, we establish a CRISPR strategy for unbiasedly probing functional amino acid residues at the genome scale. By coupling adenine base editors and barcoded sgRNAs, we target 215,689 out of 611,267 (35%) lysine codons, involving 85% of the total protein-coding genes. We identify 1,572 lysine codons whose mutations perturb human cell fitness, with many of them implicated in cancer. These codons are then mirrored to gene knockout screen data to provide functional insights into the role of lysine residues in cellular fitness. Mining these data, we uncover a CUL3-centric regulatory network in which lysine residues of CUL3 CRL complex proteins control cell fitness by specifying protein-protein interactions. Our study offers a general strategy for interrogating genetic elements and provides functional insights into the human proteome.

Ni-Ti Intercalated and Supported Bentonite for Selective Hydrogenation of Cinnamaldehyde.

Ni-Ti intercalated bentonite catalysts (Ni-Ti-bentonite) and Ni-TiO2 supported bentonite catalysts (Ni-TiO2 /bentonite) were prepared, and the effects of Ni-Ti supported and intercalated bentonite on the selective hydrogenation of cinnamaldehyde were investigated. Ni-Ti intercalated bentonite enhanced the Brønsted acid sites strength, decreased the acid amount and Lewis's acid sites strength, which inhibited the activation of the C=O bond and contributed to selective hydrogenation of the C=C bond. When Ni-TiO2 was supported on bentonite, the acid amount and Lewis's acid strength of the catalyst increased, providing additional adsorption sites and increased the acetals byproducts. Due to the higher surface area, mesoporous volume, and suitable acidity, compared with Ni-TiO2 /bentonite in methanol solvent, 2 MPa, 120 °C for 1 h, Ni-Ti-bentonite exhibited a higher cinnamaldehyde (CAL) conversion of 98.8 %, as well as a higher hydrocinnamaldehyde (HCAL) selectivity of 95 %, and no acetals were found in the product.

Distribution and Interactive Effects of Heavy Metals in Soil-Maize (Zea Mays L.) System in the Mercury Mining Area, Southwestern China.

The concentrations and interactive effects of beneficial elements (i.e., Se, Mo, and Zn) and heavy metals (As, Cd, Hg, and Pb) of maize (Zea mays L.) grown on lime soil and/or soil with mercury tailing were investigated in this study. The results show that the concentrations of heavy metals (i.e., As, Hg, and Pb) in soil with tailing were higher than those in lime soil. The concentrations of beneficial elements (i.e., Mo and Zn) in maize grown on soil with tailing were higher than those of maize grown on lime soil. The mean concentrations of Se, Mo, and Zn in maize grown on soil with tailing were 3.67 mg/kg, 0.530 mg/kg, and 27.4 mg/kg. The pH and an antagonistic effect played an important role in the concentrations of Mo and Zn in maize. The Se concentration in maize was controlled by the planting media.

Mercury Bioaccumulation in Freshwater Snails as Influenced by Soil Composition.

Soil properties largely control the fate of mercury (Hg), including the synthesis of neurovirulent methylmercury (MeHg). Here, the freshwater snail (Cipangopaludina cahayensis), a snail species commonly bred in flooded farmland, was used in a test of biotoxicity exposure to explore the effects of soil components on Hg bioavailability. The results show that snails incubated on the surface of slightly Hg-polluted flooded soil (2.0 mg/kg) have MeHg concentrations of 7.9 ± 1.5 mg/kg, which greatly exceed the limit of contaminants in food in China (0.5 mg/kg). The addition of ferrous disulfide can significantly increase the MeHg concentrations in soils while reducing the concentrations of total Hg (THg) and MeHg levels in snails by 59.1% and 64.3%, respectively. Peat-derived fulvic acid has the capacity to reduce the MeHg concentrations in soils and snails by 23.8% and 33.2%, respectively, whereas it increases the dissolved Hg levels in overlying water by 104.3%. Moreover, Fe-Mn oxides and humic acid can consistently reduce THg and MeHg concentrations in snails. Overall, freshwater snails bred in Hg-polluted areas may suffer from a high risk of Hg exposure, and importantly, some soil components such as ferrous disulfide and humic acid have strong inhibitory effects on Hg bioaccumulation in snails.

From self-construal to threat appraisal: Understanding cultural differences in social anxiety between Asian Americans and European Americans.

OBJECTIVE: Abundant research has shown that Asian Americans tend to score higher on standardized social anxiety measures than do European Americans. The current study explored how this cultural difference in social anxiety may be explained by cultural differences in self-construals and threat appraisal between Asian Americans and European Americans. METHOD: Participants were 310 Asian Americans and 249 European Americans recruited from a large university in Hawaii who completed questionnaires online in exchange for course credit. Using structural equation modeling, we compared a series of competing models in which cultural differences in social anxiety were specified to be mediated by cultural differences in self-construals and threat appraisal. RESULTS: Compared with European Americans, Asian Americans scored higher on measures of social anxiety, threat appraisal, and interdependent self-construal, and lower on independent self-construal. We found support for the mediating roles of both self-construals and threat appraisal. Specifically, higher interdependent and lower independent self-construal reported by Asian Americans were related to higher threat appraisal, which were, in turn, associated with higher social anxiety. Higher interdependent and lower independent self-construal were also directly related to higher social anxiety over and above the influence of threat appraisal. CONCLUSIONS: These findings provide initial evidence on how cultural group differences in beliefs about the self in relation to others may shape what is attended to in a social situation, and contribute to cultural differences in subsequent affective response between Asian Americans and European Americans. (PsycINFO Database Record (c) 2018 APA, all rights reserved).

Race Essentialism and Social Contextual Differences in Children's Racial Stereotyping.

The authors explored the differential emergence and correlates of racial stereotyping in 136 children ages 4-11 years across two broad social contexts: Hawai'i and Massachusetts. Children completed measures assessing race salience, race essentialism, and in-group and out-group stereotyping. Results indicated that the type of racial stereotypes emerging with age was context dependent. In both contexts in-group stereotyping increased with age. In contrast, there was only an age-related increase in out-group stereotyping in Massachusetts. Older children in Massachusetts reported more essentialist thinking (i.e., believing that race cannot change) than their counterparts in Hawai'i, which explained their higher out-group stereotyping. These results provide insight into the factors that may shape contextual differences in racial stereotyping.

Application of a clamshell isothermal nucleic acid amplification analyzer in the detection of lower respiratory tract bacteria.

Objectives: The clamshell isothermal nucleic acid amplification analyzer RTisochip-S, a next-generation instrument featuring improved structural design, enhanced functional integration, reduced cost, and increased portability, was assessed for its suitability in clinical respiratory pathogens detection. Methods: The certificated detection kit for lower respiratory tract bacteria (LRTB-kit) was applied to evaluate the performance of RTisochip-S via sensitivity, specificity, and repeatability analysis. The clinical specimens, including 51 sputum specimens and 10 bronchoalveolar lavage fluid specimens, were simultaneously detected on both RTisochip-S and a certificated reference instrument (RTisochip-A) to assess the consistency. Results: The results indicated that RTisochip-S fulfills the sensitivity, specificity, and repeatability requirements of the LRTB-Kit, and the results of clinical specimens on the two instruments were consistent. Conclusions: RTisochip-S is satisfying the clinical detection of respiratory pathogens while enhancing portability and compactness, making it more well-suited for point-of-care testing (POCT) applications.

Transcriptome Analysis and Identification of Cadmium-Induced Oxidative Stress Response Genes in Different Meretrix meretrix Developmental Stages.

Cadmium (Cd) is one of the major pollutants in the aquatic environment, and it can easily accumulate in aquatic animals and result in toxic effects by changing the metabolism of the body, causing a serious impact on the immune system, reproductive system, and the development of offspring. The clam Meretrix meretrix is one of the commercially important species that is cultivated in large-scale aquaculture in China. To elucidate the underlying molecular mechanisms of Cd2+ in the developmental processes, fertilized eggs and larvae of M. meretrix at different developmental stages were exposed to Cd2+ (27.2 mg L-1 in natural seawater) or just natural seawater without Cd2+ (control), and high-throughput transcriptome sequencing and immunohistochemistry techniques were used to analyze the toxic effects of Cd on larvae at different early developmental stages. The results revealed 31,914 genes were differentially expressed in the different stages of M. meretrix development upon treatment with Cd2+. Ten of these genes were differentially expressed in all stages of development examined, but they comprised only six unigenes (CCO, Ndh, HPX, A2M, STF, and pro-C3), all of which were related to the oxidative stress response. Under Cd exposure, the expression levels of CCO and Ndh were significantly upregulated in D-shaped and pediveliger larvae, while pro-C3 expression was significantly upregulated in the fertilized egg, D-shaped larva, and pediveliger. Moreover, HPX, A2M, and STF expression levels in the fertilized egg and pediveliger larvae were also significantly upregulated. In contrast, CCO, Ndh, HPX, A2M, STF, and pro-C3 expression levels in the postlarva were all downregulated under Cd exposure. Besides the genes with changes in expression identified by the transcriptome, the expression of two other oxidative stress-related genes (MT and Nfr2) was also found to change significantly in the different developmental stages of M. meretrix upon Cd exposure, confirming their roles in combating oxidative stress. Overall, the findings of this study indicated that Cd would interfere with cellular respiration, ion transport, and immune response through inducing oxidative stress, and changes in the expression of oxidative stress-related genes might be an important step for M. meretrix to deal with the adverse effects of Cd at different stages of its development.

"Unpacking" cultural differences in social anxiety between Japanese and European Americans: the roles of threat appraisal and attentional bias.

Introduction: Cultural differences in self-reported social anxiety between people of East Asian heritage and European heritage may be related to differences in independent and interdependent self-construals, which potentially influence the processing of social threat. Methods: We examined the roles of two different aspects of threat bias: threat appraisal (Study 1) and attentional bias (Study 2) to explain cultural group differences in social anxiety between Japanese and European American college students. Results: Study 1 demonstrated that sequential mediations of lower independent self-construal and higher appraisal of threat among Japanese could explain their higher social anxiety compared to European Americans. However, Study 2 failed to find the relation between cultural group differences in self-construals and attentional bias. In addition, the cultural group differences in attentional bias were unexpectedly due to stronger selective attention toward neutral stimuli among European Americans, rather than bias toward social threat among Japanese. After selective attention was experimentally manipulated, there were significant cultural group differences in self-reported social anxiety and anxious behavior in a speech task. Discussion: These conflicting findings suggested that an alternative theoretical framework other than the self-construal theory might be needed to fully account for cultural differences in attentional bias in explaining cultural group differences in social anxiety.

The prevalence of positive right to left shunt in migraine patients with and without aura: A new single-center study in China.

BACKGROUND: Recently, many studies have reported that there may be association between positive right-to-left shunt (RLS) and migraine, especially Migraine with aura (MA) patients. However, these researches are mostly limited in Western country. And the latest study describing the prevalence of RLS in Chinese patients with migraine was conducted five years ago. It indicated the significant higher rate of positive RLS in MA patients than migraine without aura(MWOA) group. However, no consistent results were observed according to our daily work. OBJECTIVE: To investigate the prevalence and grade of RLS in migraine patients with and without aura and to evaluate the potential association between positive RLS and migraine with aura. METHODS: A total of 91 migraine patients were involved, including 57 MWOA patients and 34 MA patients. MWOA and MA were diagnosed according to the International Classification of Headache Disorders, 3rd edition (beta version) (ICHD-3). Contrast transcranial Doppler ultra-sound (cTCD) was used to assess the prevalence of positive RLS, the associations between RLS and presence of aura. RESULTS: The overall prevalence of RLS in migraine patients was 35.2%. In MA group, 44.1% (15/34) were positive for RLS overall, higher than MWOA group (29.8%,17/57). However, the differences were not significant (P = 0.167). And there were no marked differences in the prevalence of large, middle and small shunt between MA and MWOA patients. CONCLUSION: Our study suggested MA patients have the slightly higher prevalence of positive RLS than MWOA patients in China. However, there were no significant differences, which was different from the previous studies. Our findings suggested the negative association between the positive RLS and migraine with aura.

Meta-analysis of iron metabolism markers levels of Parkinson's disease patients determined by fluid and MRI measurements.

BACKGROUND: Parkinson' s disease (PD) is a progressive neurodegenerative disease featured neuropathologically by the loss of dopaminergic neurons of the substantia nigra (SN). Iron overload in the SN is mainly relative to the pathology and pathogenesis of PD. Postmortem samples of PD has indicated the increased levels of brain iron. However, there is no consensus on iron content through iron-sensitive magnetic resonance imaging (MRI) techniques and the alteration of iron and iron related metabolism markers levels in blood and cerebrospinal fluids (CSF) are still unclear based on the current studies. In this study, we performed a meta-analysis to explore the iron concentration and iron metabolism markers levels through iron-sensitive MRI quantification and body fluid. METHODS: A comprehensive literature search was performed in PubMed, EMBASE and Cochrane Library databases for relevant published studies that analyzed iron load in the SN of PD patients using quantitative susceptibility mapping (QSM) or susceptibility weighting imaging (SWI), and iron metabolism markers, iron, ferritin, transferrin, total iron-binding capacity（TIBC）in CSF sample or serum/plasma sample (from Jan 2010 to Sep 2022 to filter these inaccurate researches attributed to unadvanced equipment, inaccurate analytical methods). Standardized mean differences (SMD) or mean differences (MD) and 95% confidence intervals (CI) with random or fixed effect model was used to estimate the results. RESULTS: Forty-two articles fulfilled the inclusion criteria including 19 for QSM, 6 for SWI, and 17 for serum/plasma/CSF sample including 2874 PD patients and 2821 healthy controls (HCs). Our meta-analysis results founded a notable difference for QSM values increase (19.67, 95% CI=18.69-20.64) and for SWI measurements (-1.99, 95% CI= -3.52 to -0.46) in the SN in PD patients. However, the serum/plasma/CSF iron levels and serum/plasma ferritin, transferrin, total iron-binding capacity (TIBC) did not differ significantly between PD patients and HCs. CONCLUSIONS: Our meta-analysis showed the consistent increase in the SN in PD patients using QSM and SWI techniques of iron-sensitive MRI measures while no significant differences were observed in other iron metabolism markers levels.

The Effects of Different Soil Component Couplings on the Methylation and Bioavailability of Mercury in Soil.

Soil composition can influence the chemical forms and bioavailability of soil mercury (Hg). However, previous studies have predominantly focused on the influence of individual components on the biogeochemical behavior of soil Hg, while the influence of various component interactions among several individual factors remain unclear. In this study, artificial soil was prepared by precisely regulating its components, and a controlled potted experiment was conducted to investigate the influence of various organic and inorganic constituents, as well as different soil textures resulting from their coupling, on soil Hg methylation and its bioavailability. Our findings show that inorganic components in the soils primarily exhibit adsorption and fixation effects on Hg, thereby reducing the accumulation of total mercury (THg) and methylmercury (MeHg) in plants. It is noteworthy that iron sulfide simultaneously resulted in an increase in soil MeHg concentration (277%). Concentrations of THg and MeHg in soil with peat were lower in rice but greater in spinach. A correlation analysis indicated that the size of soil particles was a crucial factor affecting the accumulation of Hg in plants. Consequently, even though fulvic acid activated soil Hg, it significantly increased the proportion of soil particles smaller than 100.8 µm, thus inhibiting the accumulation of Hg in plants, particularly reducing the concentration of THg (93%) and MeHg (85%) in water spinach. These results demonstrate that the interaction of organic and inorganic components can influence the biogeochemical behavior of soil Hg not only through their chemical properties, but also by altering the soil texture.

SARS-CoV-2 transmission via maritime cold chains: A statistical analysis of nucleic acid detection results of cold chain food imported from Fuzhou ports.

Numerous epidemic outbreaks related to cold chains have occurred since the coronavirus disease 2019 (COVID-19) outbreak, suggesting the potential danger of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) transmission through cold chain foods (CCFs). By analyzing SARS-CoV-2 RNA contamination of CCFs imported from Fuzhou ports, this study evaluated the contamination and transmission of SARS-CoV-2 RNA via maritime cold chains, with the aim of provide suggestions for CCFs supervision and public health management. The statistical analysis included 131,385 samples. The majority of the CCFs imported into Fuzhou ports was aquatic raw food that originated in Southeast Asia (57.08 %), South America (19.87 %), and South Asia (11.22 %). South Asia had the highest positivity rate of 0.37 %, followed by Southeast Asia (0.21 %) and South America (0.08 %). The positivity rate showed that the outer packaging of CCFs was the most easily contaminated, accounting for 81.33 % of all positive samples. This suggested that CCFs storage and loading processes were the weak links vulnerable to SARS-CoV-2 contamination. The positivity rates in outer packaging, inner packaging, and content of raw food were 0.48 %, 0.08 %, and 0.05 %, respectively, which were obviously higher than those of processed and refined food. This indicated that increasing the mechanization of factories and implementing sensible worker management practices may decrease viral contamination. The monthly positivity rates varied widely from 0 % (March 2021) to 0.40 % (January 2021), with an average of 0.19 %. The positivity rates in outer packaging, inner packaging and content of crustaceans from Southeast Asia were 2.47 %, 0.41 %, and 0.69 %, which were approximately 5-14 times higher than those of fish and cephalopods. Meanwhile, the monthly detection number show that SARS-CoV-2 epidemic prevention strategies affected the trade of imported CCFs.

Advanced strategies for metabolic engineering of Bacillus to produce extracellular polymeric substances.

Extracellular polymeric substances are mainly synthesized via a variety of biosynthetic pathways in bacteria. Bacilli-sourced extracellular polymeric substances, such as exopolysaccharides (EPS) and poly-γ-glutamic acid (γ-PGA), can serve as active ingredients and hydrogels, and have other important industrial applications. However, the functional diversity and widespread applications of these extracellular polymeric substances, are hampered by their low yields and high costs. Biosynthesis of extracellular polymeric substances is very complex in Bacillus, and there is no detailed elucidation of the reactions and regulations among various metabolic pathways. Therefore, a better understanding of the metabolic mechanisms is required to broaden the functions and increase the yield of extracellular polymeric substances. This review systematically summarizes the biosynthesis and metabolic mechanisms of extracellular polymeric substances in Bacillus, providing an in-depth understanding of the relationships between EPS and γ-PGA synthesis. This review provides a better clarification of Bacillus metabolic mechanisms during extracellular polymeric substance secretion and thus benefits their application and commercialization.

Identification of Candidate Genes Associated with Development of Vascular Cognitive Impairment by Integrated Bioinformatics Analysis Combined with Biological Experiments.

The morbidity and mortality associated with vascular cognitive impairment (VCI) generally increase steeply, and health systems will face increasing demand for services. The present study aims to screen key genes to give new insight into the mechanisms and treatment of VCI based on bioinformatic approaches combined with biological experiments in rats. The gene expression data of VCI patients contained in the GSE122063 dataset were downloaded from the GEO. We performed a weighted gene co-expression network analysis (WGCNA) to identify a hub module and 44 hub genes.277 differentially expressed genes (DEGs) were analyzed using R software by the "limma" package. STRING database was used to construct protein-protein interaction (PPI) network, after which 36 hub genes were identified through Cytoscape. Functional enrichment analysis revealed that these genes from the yellow module and 277 DEGs were mainly associated with these pathways, such as staphylococcus aureus infection, complement, and coagulation cascades. These biological functions are related to inflammatory cell activation and inflammatory response. The key genes of VCI were the overlapping hub genes from the yellow module and the PPI network. The expressions of hub genes in rats were determined by qRT-PCR, western blot, immunohistochemistry, and immunofluorescence. In conclusion, C1QA, C1QB, C1QC, CD163, and FCGR2A were highly expressed in the hippocampus of VCI rats, and they can serve as candidate biomarkers for the diagnosis and prognosis of VCI. Finally, molecular docking results suggested that five genes interact with Bisphenol A. These findings open a new avenue to investigate molecular mechanisms for preventing or treating vascular cognitive impairment.

Evaluation of a novel lyophilized-pellet-based 2019-nCoV nucleic acid detection kit for the diagnosis of COVID-19.

The coronavirus disease 2019 (COVID-19) caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has swept the world and poses a serious threat to human health. In the post-pandemic-era, we must remain vigilant against the co-infection of SARS-CoV-2 and other respiratory viruses. More accurate and convenient detection methods are required for the diagnosis of SARS-CoV-2 due to its prolonged existence. In this study, the application value of a novel lyophilized-pellet-based 2019-nCoV nucleic acid diagnostic kit (PCoV-Kit) was evaluated by comparing it with a conventional liquid diagnostic kit (LCoV-Kit). We assessed the sensitivity, precision, accuracy, specificity, and amplification efficiency of PCoV-Kit and LCoV-Kit using diluted SARS-CoV-2 RNA reference materials. The results showed that both kits had high sensitivity, precision, accuracy, and specificity. A total of 2,033 oropharyngeal swab specimens collected during mass screening in Fuzhou in December 2022 were applied for the consistency analysis of the two reagents. In the detection of clinical oropharyngeal swab specimens, although the positive rate of PCoV-Kit (19.28%) was slightly lower than that of LCoV-Kit (20.86%), statistical analysis demonstrated a high degree of consistency between the test results obtained using both kit (χ2 = 1.57, P>0.05; Kappa coefficient = 0.90, 95%CI: 0.88-0.93). In conclusion, the use of lyophilized PCoV-Kit provides a non-inferior assay for the diagnosis of COVID-19.

Selenium/sulfur-modified montmorillonite materials mitigate mercury pollution in farmland.

Selenium (Se) amendment could reduce mercury (Hg) bioaccumulation in crops, but sometimes it could cause excessive Se accumulation in crops and potential Se exposure risks for humans. In this study, we designed and synthesized selenium and sulfur-modified montmorillonite materials (Se/S-Mont) to effectively reduce mercury levels and avoid excessive Se enrichment in plants. The results of pot experiments (1 g Se/S-Mont/100 g soil) and field microplot trials (0.3 g Se/S-Mont/100 g soil, 8 t/ha) showed that Se/S-Mont amendments significantly reduced the Hg concentrations in water spinach and hybrid Pennisetum by 28-68% and 57%-92% (P < 0.05), respectively, while they did not lead to excessive Se bioaccumulation in the plants. Se/S-Mont was more efficient in mitigating soil Hg pollution than adding raw materials (e.g., NaSeO3) and their combinations, and they significantly reduced the available Se fraction in the soil and the Se levels in the plants (P < 0.05). The potential mechanisms revealed by X-ray absorption near-edge spectra (XANES) and pot experiments were the adsorption and slow release of Hg, S, and Se by Se/S-Mont, the high affinity between Hg and Se, competition between Se and S, and the formation of stable complexes containing Se-S-Hg. The Se/S-Mont immobilizer was easy to prepare and required the application of small amounts, and the remediation effect was relatively stable and exhibited few negative effects; therefore, the approach showed high environmental and economic potentials.

Evaluation of the effects of long-term natural and artificial restoration on vegetation characteristics, soil properties and their coupling coordinations.

Vegetation restoration is the most important factor to restrain soil and water loss in the Chinese Loess Plateau, and its effect is long-term. Among them, the coupling and coordination relationship between vegetation and soil is the key to the smooth implementation of ecological restoration and the project of returning farmland to forest and grassland. However, people have neglected whether the choice of vegetation restoration method is suitable for the development of ecological environment in this region, and whether vegetation and soil coexist harmoniously. In this paper, the typical watersheds with similar terrain environment but different vegetation restoration methods were selected as the research objects, which were Dongzhuanggou (natural restoration, NR) and Yangjiagou (artificial restoration, AR). Through vegetation investigation and soil physical property experiment, the comprehensive evaluation function was used to quantify the impact of restoration methods on vegetation characteristics and soil properties, and the vegetation-soil coupling model was used to explore the coordinated development of vegetation and soil under different restoration methods. The results showed that there were significant differences between the two restoration methods in terms of vegetation characteristics (P < 0.05). The vegetation diversity indices of NR were 1.59-4.81 times that of AR. For root characteristic indices, NR was 1.05-2.25 times that of AR. For soil physical properties, there was no significant difference between the two restoration methods (P > 0.05). The comprehensive evaluation function of vegetation (VCE) and soil (SCE) under NR were 0.74 and 0.42, respectively, while those under AR were 0.55 and 0.63, respectively. The comprehensive function showed that the vegetation population performance under NR was slightly better than that under AR, while the soil restoration effect was opposite. Under the two restoration methods, the vegetation-soil coupling relationship was barely coordinated (NR: 0.53; AR: 0.54), and both were the intermediate coordinated development mode. The vegetation diversity, tending level and soil management level should be improved simultaneously during the process of vegetation restoration on the Chinese Loess Plateau.

Distribution and dispersion of heavy metals in the rock-soil-moss system of the black shale areas in the southeast of Guizhou Province, China.

Black shales are easily exposed due to human activities such as mining, road construction, and shale gas development, which results in several environmental issues including heavy metal (HM) pollution, soil erosion, and the destruction of vegetation. Mosses are widely used to monitor metal pollution in the atmosphere, but few studies on the distribution and dispersion of HMs in the rock-soil-moss system are available. Here, mosses (Pohlia flexuosa Harv. in Hook), growing soils, and corresponding parent rocks were collected from black shale areas. After appropriate pretreatment, samples were analyzed for multiple elemental concentrations by ICP-AES and ICP-MS. The results show that black shale parent rocks have elevated HM concentration and act as a source of multiple metals. The overlying soil significantly inherits and accumulates heavy metals released from black shale. Significant positive correlations between HMs in P. flexuosa and the growing soils indicate that HMs are mainly originating from geological source rather than atmospheric deposition. Differential accumulation of HMs is observed between rhizoids and stems in our study. Moreover, P. flexuosa is able to cope with high concentrations of toxic metals without any visible negative effect on its growth and development. Finally, the bioconcentration factor (BCF) for all the HMs in P. flexuosa is less than 1, indicating that it has a tolerance and exclusion mechanism for these metals, especially for the non-essential elements As and Pb. Therefore, the luxuriant and spontaneous growth of P. flexuosa could be used as a phytostabilization pioneer plant in the black shale outcrop where vascular plants are rare.