Combined effects of aquifer heterogeneity and subsurface dam on nitrate contamination in coastal aquifers.

Subsurface dams are effective for seawater intrusion mitigation, yet they can cause upstream nitrate accumulation. This research examines the interplay between subsurface dam construction and aquifer layering on nitrate pollution in coastal settings, employing numerical models to simulate density-driven flow and reactive transport. The study reveals that while subsurface dams are adept at curbing seawater intrusion, they inadvertently broaden the nitrate accumulation zone, especially when a low-K layer is present. Heterogeneous aquifers see more pronounced nitrate accumulation from subsurface dams. This effect is pronounced as it influences dissolved organic carbon dynamics, with a notable retreat inland correlating with the expansion of the nitrate pollution plume. A critical finding is that controlling seawater intrusion via dam height adjustment within the Effective Damming Region effectively reduces nitrate levels and bolsters freshwater output. However, exceeding the critical threshold-where the dam surpasses the low-K layer's bottom-results in a substantial shift in nitrate concentration, underscoring the need for precise dam height calibration to avoid aggravating nitrate pollution. This study's innovative contribution lies in its quantification of the nuanced effects of subsurface dams in stratified aquifers, providing an empirical basis for dam design that considers the layered complexities of coastal aquifers. The insights offer a valuable framework for managing nitrate contamination, thus informing sustainable coastal groundwater management and protection strategies.

Dynamic influence of land reclamation on the nitrate contamination and saltwater redistribution.

Previous research concerning the effect of land reclamation on seawater intrusion mostly focused on the modification of the saltwater wedge and the dynamics of freshwater-saltwater interface after land reclamation, utilizing both analytical and numerical models. So far, the impact of land reclamation on the recharging and accumulation of land-based pollutants such as nitrate has been disregarded. In this work, we are the first to examine the impact of land reclamation on the discharge of nitrate together with the movement of saltwater. The influence of reclamation area and filled soil permeability on nitrate pollution and saltwater redistribution is revealed using a series of field-scale simulations based on numerical models including density flow combined with reactive transport. It was discovered that land reclamation might, on the one hand, result in a substantial redistribution based on the initial saltwater-freshwater interface and, on the other hand, significantly modify the nitrate discharge. This in total would drastically alter the distribution of nitrate in the subsurface. The reclamation area and the permeability of the reclamation material are the two elements that determine the amount of variance. For the cases with hydraulic conductivities increasing from 5 to 50 m/d, the salt mass reduction rate showed a trend of first increased (84.78 %-95.58 %) and then slowly decreased (95.58 %-74.01 %). Meanwhile, the nitrate reduction rate decreased from 80.08 % to 12.93 %, when hydraulic conductivities increased from 5 to 50 m/d. It was also found that coastal nitrate accumulation was always intensified with the enlargement of the reclamation area. Finally, we are able to assist engineers in optimizing their land reclamation strategies by taking into account both the degree of saltwater intrusion and nitrate enrichment.

Mediating role of perceived social support in the relationship between perceived stress and job burnout among midwives in the post-COVID-19 era.

AIM: The aim of this study was to explore the mediating role of perceived social support in the association between perceived stress and job burnout in midwives. DESIGN: A descriptive, cross-sectional online survey. METHODS: Using the stratified cluster sampling method, 329 midwives in 20 hospitals in China were selected as the participants. They completed self-report assessment measures of job burnout, perceived stress and perceived social support. RESULTS: 63.5% of the participants had job burnout. Perceived stress was negatively associated with social support (r = -.350, p < .01), while it was positively associated with job burnout (r = -.382, p < .01). Social support was negatively correlated with job burnout (r = -.569, p < .01). The total effect of perceived stress on job burnout was 0.474 (95% CI: 0.367 ~ 0.596, p < .01), the direct effect was 0.242 (95% CI: 0.142 ~ 0.355, p < .01), and the indirect effect was 0.232 (95% CI: 0.160 ~ 0.316, p < .01). Social support programmes for midwives should be implemented to control the impact of perceived stress on job burnout.

LncRNA CASC9-1 Facilitates Cell Malignant Behaviors in Cervical Squamous Cell Carcinoma by Targeting miR-383-5p to Up-regulate MAPKAP1.

BACKGROUND: Cervical squamous cell carcinoma (Cervical SCC) is a malignant gynecological tumor, which greatly endangers the health of global women. Cancer susceptibility candidate 9 (CASC9) has been identified as an oncogene in multiple cancers. However, the role of CASC9-1 (one transcript of CASC9) in cervical SCC remains covered. METHODS: We analyzed gene expression in cervical SCC cells via RT-qPCR and western blot assays. The impact of CASC9-1 on cervical SCC cell and tumor growth was assessed via in vitro functional assays and in vivo assays. Moreover, the regulatory mechanism of CASC9-1 was explored by mechanism assays. RESULTS: CASC9-1 was up-regulated in cervical SCC cells. CASC9-1 knockdown repressed cervical SCC cell proliferation, migration and invasion while elevating apoptosis. Via in-vivo experiments, CASC9-1 down-regulation was proved to restrict cervical SCC tumor growth. In terms of mechanism, CASC9-1 directly targeted miR-383-5p, and MAPKAP1 was the target gene of miR-383-5p in cervical SCC cells. CASC9-1 could exacerbate malignant behaviors of cervical SCC cells via binding to miR-383-5p and regulating MAPKAP1. CONCLUSIONS: CASC9-1 exerted influences on various biological behaviors of cervical SCC cells via targeting miR-383-5p to up-regulate MAPKAP1. All these results mirrored that CASC9-1 might be a potential target for cervical SCC treatment.

TGFß/Smad mediated the polyhexamethyleneguanide areosol-induced irreversible pulmonary fibrosis in subchronic inhalation exposure.

AIM: Polyhexamethylene guanidine (PHMG) is widely used as a disinfectant with broad spectra of bactericidal activity and low oral toxicity. However, inhalation of PHMG can cause pulmonary injury and severe pulmonary fibrosis. The mechanism underlying PHMG aerosol induced pulmonary fibrosis remains unclear. In this study, we aimed to examine the subchronic lung injury and determine potential cytokines involved in PHMG aerosol induced fibrosis. METHODS: C57BL/6N mice were exposed to 1.03 mg/m3 PHMG through aerosol inhalation for 3 weeks, or 3 weeks followed by other 3 weeks recovery. RESULTS: The results indicated that the expression of transforming growth factor-beta1 (TGF-ß1) and extracellular matrix remodeling markers were up-regulated in the PHMG-treated mice and these parameters were aggravated after 3 weeks recovery. Bronchoalveolar lavage fluids (BALFs) analysis showed that the number of total cells was significantly decreased in exposure group. The percentage of macrophages in BALFs decreased significantly whereas the percentage of neutrophils and lymphocytes increased. Extensive collagen deposition was observed in the peribronchiolar and interstitial areas in the PHMG exposed lungs. CONCLUSION: In conclusion, even low-does PHMG aerosol exposure could induce mice pulmonary local inflammation and irreversible fibrosis. In addition, TGF-ß/Smad signaling pathway mediated the extracellular matrix remodeling involved in the development of pulmonary fibrosis.

Phenotypic plasticity vs. local adaptation in quantitative traits differences of Stipa grandis in semi-arid steppe, China.

Whether plants are able to adapt to environmental changes depends on their genetic characteristics and phenotypic plastic responses. We investigated the phenotypic responses of 7 populations of an important dominant species in semi-arid steppe of China - Stipa grandis, and then distinguished which adaptive mechanism(s), phenotypic plasticity or local adaptation, was/were involved in this species to adapt to environmental changes. (1) All traits were significantly influenced by the interaction of population and growth condition and by population in each condition, and inter-population variability (CVinter) was larger in the field than in the common garden for 8/9 traits, indicating that both phenotypic plasticity and genetic differentiation controlled the phenotypic differences of S. grandis. (2) From a functional standpoint, the significant relationships between the values of traits in the common garden and the environmental variables in their original habitats couldn't support local habitat adaptation of these traits. (3) Low CVintra, low quantitative differentiation among populations (Q ST ), and low plasticity shown in the western populations indicated the very low adaptive potential of S. grandis to environmental changes. (4) From the original habitats to the common garden which is far away from S. grandis distribution region, positive phenotypic responses were found in several populations, indicating that some original habitats have become unfavorable for S. grandis.

Drought and grazing drive the retrogressive succession by changing the plant-plant interaction of the main species in Inner Mongolia Steppe.

Plant-plant interactions play a key role in the function and structure of communities. The combined effect of drought stress and grazing disturbance on shaping plant-plant interactions is still poorly understood, while this combination is common in semiarid ecosystems. Four species including Stipa grandis, which is dominant in the typical steppe, and Stipa krylovii, Artemisia frigida, and Cleistogenes squarrosa, which are dominant species in the S. grandis degraded communities, were selected as study targets. We conducted a competition experiment (uniformly dense monoculture or mixture, respectively) under controlled conditions, including both drought stress and mowing disturbance, and calculated the relative interaction index (RII) of tiller number and RII of biomass for each species under each condition. (a) Under the same condition, the RII of tiller number and that of biomass for the same species usually showed reverse trends. (b) Mowing disturbance rather than drought stress played a negative role in influencing S. grandis' or S. krylovii's RII of tiller number and played a positive role in influencing A. frigida's RII of biomass. (c) Drought stress rather than mowing disturbance played a positive role in influencing C. squarrosa's RII of tiller number. (d) Neighbor species significantly influenced S. grandis' RII of tiller number, S. krylovii's RII of tiller number, A. frigida's RII of tiller number and biomass, and C. squarrosa's RII of biomass. These results could provide an explanation for why S. krylovii, A. frigida, and C. squarrosa can replace S. grandis and become the dominant species when S. grandis communities undergo a process of degradation due to overgrazing or climatic drought in natural communities. The present study provided powerful evidences for species replacement in the typical steppe of Inner Mongolia and elucidated the driving mechanisms of S. grandis communities' retrogressive succession.

The complete mitochondrial genome of Jinshaia sinensis (Teleostei, Balitoridae, Balitorinae).

Jinshaia sinensis is an endemic and typical fish which is successfully adaptive to mountain torrents in the upper stream of the Yangtze River and its tributaries. In this study, the complete mitogenome sequence of J. sinensis has been first sequenced by DNA sequencing based on the PCR fragments. The mitogenome, consisting of 16,567 base pairs (bp), had typical vertebrate mitochondrial gene arrangement, including 13 protein coding genes, 22 transfer RNAs, 2 ribosomal RNA genes and a noncoding control region (CR). The overall base composition of J. sinensis is 30.37% A, 28.82% C, 16.59% G, and 24.22% T, with a relatively a slight AT bias of 54.59%. CR of 903 bp length is located between tRNA(Pro) and tRNA(Phe). The complete mitochondrial genome may provide fundamental informative data not only for unravel the population structure and differentiation, but also for further conservation genetics studies on this balitorid species.

[Serum antibody response and Hantavirus RNA sequencing in patients with hemorrhagic fever renal syndrome in Yantai areas].

OBJECTIVE: To understand antibody responses to and RNA sequences of Hantavirus in patients with hemorrhagic fever renal syndrome (HFRS) in Yantai areas and to demonstrate the type of the prevalent viruses caused HFRS. METHODS: Serum specimens collected at acute and convalescent stages from 90 patients with HFRS and IgM and IgG antibodies against Hantavirus were detected with ELISA, and cross plaque reduction neutralizing tests were performed to detect neutralizing antibody. Viral RNA was extracted from the patients? sera by using Trizol method and nested PCR was utilized to amplify the specific segments of the viral cDNA and the products of the PCR were TA cloned and then the nucleotide sequences were determined. RESULTS: The IgM antibody was positive in 82.2% (88/107) of the patients while the IgG antibody was positive in 85.7% (66/77) of the patients. Both the serologic and sequence analyses demonstrated that the epidemic of HFRS in Yantai areas was caused by mixed types of Hantavirus. The prevalent strains of Hantavirus had higher homology with the strains isolated in Korea than with those isolated previously in China. CONCLUSIONS: The serologic and sequencing analyses indicated that the epidemic of HFRS in Yantai areas was caused by mixed types of Hantavirus dominated by type SEO.