The significance of CD4+ and CD8+ T lymphocyte infiltration in esophageal squamous cell carcinoma.

PURPOSE: To investigate the relationship between the abundance of CD4+ and CD8+ T cells in the tumor microenvironment and the prognosis of patients with esophageal squamous cell carcinoma, and to analyze their correlation and explore its clinical value. MATERIALS AND METHODS: In total, we enrolled 120 cases of esophageal squamous cell carcinoma diagnosed. The abundance of CD4+ and CD8+ T lymphocytes in the tissue specimens of esophageal cancer was examined by immunohistochemistry. We measured the correlation between the abundance of CD4+ and CD8+ T lymphocytes and the clinical and pathological characteristics and prognosis of esophageal squamous cell carcinoma. RESULTS: The tissue abundance of CD4+ T lymphocytes was closely related to tumor prognosis (P < 0.05). Similarly, there was a statistically significant relationship between the tissue abundance of CD8+ T lymphocytes and patients' prognosis (P < 0.05), indicating that a high abundance of CD8+ T lymphocytes predicts better prognosis in esophageal squamous cell carcinoma. Surprisingly, we found that a higher CD4+/CD8+ ratio predicted a better prognosis of esophageal squamous cell carcinoma. CONCLUSIONS: The tissue abundance of CD4+ and CD8+ T lymphocytes can serve as an important indicator for predicting the long-term survival of patients with esophageal squamous cell carcinoma. A high CD4+/CD8+ ratio may improve patients' prognosis through several pathways. The association of this ratio with clinical and pathological characteristics may explain the poor efficacy of immunotherapy in patients with esophageal cancer. These findings may help us find new targets for immunotherapy by exploring the immune microenvironment of esophageal squamous cell carcinoma.

Single-cell RNA sequencing reveals aberrant sphingolipid metabolism in non-small cell lung cancer impacts tumor-associated macrophages and stimulates angiogenesis via macrophage inhibitory factor signaling.

BACKGROUND: Sphingolipids not only serve as structural components for maintaining cell membrane fluidity but also function as bioactive molecules involved in cell signaling and the regulation of various biological processes. Their pivotal role in cancer cell development, encompassing cancer cell proliferation, migration, angiogenesis, and metastasis, has been a focal point for decades. However, the contribution of sphingolipids to the complexity of tumor microenvironment promoting cancer progression has been rarely investigated. METHODS: Through the integration of publicly available bulk RNA-seq and single-cell RNA-seq data, we conducted a comprehensive analysis to compare the transcriptomic features between tumors and adjacent normal tissues, thus elucidating the intricacies of the tumor microenvironment (TME). RESULTS: Disparities in sphingolipid metabolism (SLM)-associated genes were observed between normal and cancerous tissues, with the TME characterized by the enrichment of sphingolipid signaling in macrophages. Cellular interaction analysis revealed robust communication between macrophages and cancer cells exhibiting low SLM, identifying the crucial ligand-receptor pair, macrophage inhibitory factor (MIF)-CD74. Pseudo-time analysis unveiled the involvement of SLM in modulating macrophage polarization towards either M1 or M2 phenotypes. Categorizing macrophages into six subclusters based on gene expression patterns and function, the SPP1+ cluster, RGS1+ cluster, and CXCL10+ cluster were likely implicated in sphingolipid-induced M2 macrophage polarization. Additionally, the CXCL10+, AGER+, and FABP4+ clusters were likely to be involved in angiogenesis through their interaction with endothelial cells. CONCLUSION: Based on multiple scRNA-seq datasets, we propose that a MIF-targeted strategy could potentially impede the polarization from M1 to M2 and impair tumor angiogenesis in low-SLM non-small cell lung cancer (NSCLC), demonstrating its potent antitumor efficacy.

Protein expression of nucleolar protein 12 in the retina and its implication in protection of retina from UV irradiation damage.

Nucleolar protein 12 (NOL12), one of the nucleolar proteins which are primarily expressed in the nucleolus and play key roles in RNA metabolism, cell proliferation, cell cycle, and cell survival, is widely expressed in various species and multiple organs. Although it has been reported that the mRNA of Drosophila NOL12 homolog viriato is expressed in the eyes of Drosophila, the protein expression of NOL12 in mammalian eyes remains to be elucidated. In this study, we showed through immunohistochemistry that NOL12 was present in the rat retina, with predominant distribution in the cytoplasm of the retinal neuronal cells. In the human retinoblastoma cell line WERI-Rb1, we found that altering NOL12 expression led to a change in WERI-Rb1 cell viability. Knocking down NOL12 expression decreased cell viability. In contrast, overexpressing NOL12 increased cell viability. Furthermore, increasing NOL12 expression inhibited ultraviolet (UV)-induced apoptosis. These findings demonstrated that NOL12 may play an important protective role in retinal cells. In the WERI-Rb1 cells exposed to UV irradiation, we detected that NOL12 was degraded, but this degradation could be attenuated by a pan-Caspase inhibitor. Notably, the inhibitory effect of NOL12 against UV-induced apoptosis could be restrained by increasing the expression of ATR serine/threonine kinase (ATR), a kinase that, when activated by severe DNA damage, can result in apoptosis. We also found that upregulating NOL12 inhibited the activation of ATR caused by UV irradiation. Additionally, inhibiting ATR activity reduced apoptosis resulting from both silencing NOL12 expression and UV exposure. Thus, NOL12 may protect against UV irradiation-induced retinal damage by inhibiting ATR activity.

A Novel Peptide COX52-69 Inhibits High Glucose-induced Insulin Secretion by Modulating BK Channel Activity.

BACKGROUND: Excessive insulin is the leading cause of metabolic syndromes besides hyperinsulinemia. Insulin-lowering therapeutic peptides have been poorly studied and warrant urgent attention. OBJECTIVE: The main purpose of this study, was to introduce a novel peptide COX52-69 that was initially isolated from the porcine small intestine and possessed the ability to inhibit insulin secretion under high-glucose conditions by modulating large conductance Ca2+-activated K+ channels (BK channels) activity. METHODS AND RESULTS: Enzyme-linked immunosorbent assay results indicate that COX52-69 supressed insulin release induced by high glucose levels in pancreatic islets and animal models. Furthermore, electrophysiological data demonstrated that COX52-69 can increase BK channel currents and hyperpolarize cell membranes. Thus, cell excitability decreased, corresponding to a reduction in insulin secretion. CONCLUSION: Our study provides a novel approach to modulate high glucose-stimulated insulin secretion in patients with hyperinsulinemia.

Multifunctional composite films based on polyvinyl alcohol, quaternary ammonium salt modified cellulose nanofibers and tannic acid-iron ion coordination complexes for food packaging.

The development of sustainable and well-performing food packaging materials takes on critical significance, whereas it is still challenging. To overcome the shortcomings of polyvinyl alcohol (PVA) as a degradable packaging material, in this work, hydrophobic quaternary ammonium salt (QAS) modified cellulose nanofibers (CNF) and tannic acid­iron ion coordination complexes (TA-Fe) were adopted for the preparation of functional PVA films. The modified CNF (CNF-QAS) not only improved the mechanical properties and water resistance of PVA, but also endowed it with antibacterial ability. In addition, the synergistic antibacterial capability with CNF-QAS was achieved using TA-Fe with photothermal therapy. As a result, the modulus, elongation at break, tensile strength, and water contact angle of the prepared PVA films were examined as 88 MPa, 200 %, 11.7 MPa, and 94.8°, respectively. Furthermore, with the assistance of CNF-QAS and TA-Fe, the films inhibited the growth of E. coli and S. aureus by 99.8 % and 99.7 %, respectively, and they exhibited high cell viability of 90.5 % for L929 fibroblasts. Based on the above encouraging properties, the functional PVA films could significantly extend the shelf life of oranges for over two weeks, proving the excellent application prospects in the food packaging field.

[Characteristics and Driving Mechanisms of Shallow Groundwater Chemistry in Xining City].

Groundwater is one of the major sources of water supply, especially in the western arid regions. However, with the deepening of the western development strategy, industrialization and urbanization have increased groundwater resource demands in Xining City. Overexploitation and utilization have led to a series of changes in the groundwater environment. Identifying the chemical evolution characteristics and formation mechanism of groundwater is crucial for preventing its deterioration and ensuring sustainable use. By combining hydrochemistry and multivariate statistical techniques, the chemical characteristics of groundwater in Xining City were analyzed, and the formation mechanism of groundwater and the influence of different factors were discussed. The results showed that there were as many as 36 chemical types of shallow groundwater in Xining City, mainly HCO3-Ca(Mg) (60.00%) and HCO3·SO4-Ca(Mg) (11.81%). There were 5-6 types of groundwater chemical types in bare land, grassland, and woodland. Groundwater chemical types in construction land and cultivated land were more complex, up to 21 types, indicating that they were strongly affected by human activities. The chemical evolution process of groundwater in the study area was mainly affected by rock weathering and leaching, evaporative crystallization, and cation exchange. The main controlling factors were water-rock interaction (contribution rate 27.56%) and industrial wastewater discharge (contribution rate 16.16%), acid-base environment (contribution rate 16.00%), excessive application of chemical fertilizers and pesticides (contribution rate 13.11%), and domestic sewage (contribution rate 8.82%). On account of the chemical characteristics of groundwater in Xining City and the influence of human activities, the management and control suggestions on the development and utilization of groundwater resources were put forward.

MicroRNA-29a-3p Prevents Drug-Induced Acute Liver Failure through Inflammation-Related Pyroptosis Inhibition.

OBJECTIVE: Little is known about the role of microRNA-29a-3p (miR-29a-3p) in inflammation-related pyroptosis, especially in drug-induced acute liver failure (DIALF). This study aimed to identify the relationship between miR-29a-3p and inflammation-related pyroptosis in DIALF and confirm its underlying mechanisms. METHODS: Thioacetamide (TAA)- and acetaminophen (APAP)-induced ALF mouse models were established, and human samples were collected. The expression levels of miR-29a-3p and inflammation and pyroptosis markers were measured by quantitative real-time polymerase chain reaction (qRT-PCR), Western blotting, or immunochemical staining in miR-29a-3p knock-in transgenic mouse (MIR29A(KI/KI)) DIALF models. In addition, RNA sequencing was conducted to explore the mechanisms. RESULTS: MiR-29a-3p levels were decreased in TAA- and APAP-induced DIALF models. MiR-29a-3p prevented DIALF caused by TAA and APAP. RNA sequencing and further experiments showed that the protective effect of miR-29a-3p on DIALF was mainly achieved through inhibition of inflammation-related pyroptosis, and the inhibition was dependent on activation of the PI3K/AKT pathway. In addition, miR-29a-3p levels were reduced, and pyroptosis was activated in both peripheral blood mononuclear cells and liver tissues of DIALF patients. CONCLUSION: The study supports the idea that miR-29a-3p inhibits pyroptosis by activating the PI3K/AKT pathway to prevent DIALF. MiR-29a-3p may be a promising therapeutic target for DIALF.

[Hydrochemical and Isotopic Evidence for Groundwater Conversion of Surface Water in Alpine Arid Areas: A Case Study of the Datong River Basin].

Global warming and regional extreme climates will lead to unbalanced rainfall, melting glaciers, and permafrost degradation in alpine and arid mountain plains, thereby changing the regional hydrological cycle. The relationship between surface water and groundwater conversion is one of the important scientific issues of hydrological cycle climate response in alpine arid areas. Taking the Datong River Basin at the southern foot of the Qilian Mountains as the study area, based on 119 sets of basic hydrochemical parameters and deuterium-oxygen isotope data, using multivariate statistical analysis and isotopic techniques, the hydrochemical characteristics of surface water and groundwater in the basin and their mutual transformation process were studied. The results showed that the surface water was HCO3-Mg·Ca type, which was mainly controlled by rock weathering, whereas the groundwater was HCO3-Mg·Ca type and Cl·SO4-Na type, which was controlled by rock weathering and evaporation concentration. There was a small amount of calcium and magnesium feldspar dissolved in the upstream groundwater, and the chemical components of the midstream groundwater were mainly the weathering and dissolution of carbonate rocks. The contribution rates of weathering filtration, anthropogenic activities, native sedimentary environment, alternating adsorption of cations, and other factors to the chemical components of surface water and groundwater in the study area were 39.1%, 15.0%, 12.6%, 13.8%, and 19.5%, respectively. The deuterium and oxygen isotope contents of Datong River water showed a trend of enrichment to depletion along the groundwater flow direction. The δD and δ18O isotope test results showed that the deuterium and oxygen isotope content in the Datong River along the groundwater flow showed a trend of enrichment to depletion. The upper and middle reaches of the Datong River were mainly recharged by atmospheric precipitation, whereas the lower reaches were affected by geological structure and influenced by hydrogeological conditions, which was mainly due to diving and spring water overflow to supply river water, as the discharge area of groundwater.

[Analysis on Contamination Characteristics, Pollution Source Identification and Ecological Risk Assessment of Polycyclic Aromatic Hydrocarbons of Groundwater in a Large Coking Plant Site of Province].

Polycyclic aromatic hydrocarbons (PAHs), as a highly toxic persistent organic pollutant, are commonly found in soil and water environments. In recent years, the pollution of PAHs in groundwater has attracted wide attention from scientists. To study the pollution characteristics and sources of polycyclic aromatic hydrocarbon in groundwater of the coking site, 16 PAHs priorly controlled by the US EPA were analyzed and discussed. In this study, we identified the contamination characteristics of PAHs in groundwater, analyzed the pollution sources of PAHs, and evaluated the ecological risk of PAHs in the coking site by combining statistical techniques, the positive matrix factorization (PMF) model, and risk quotient (RQ) methods. The results indicated that the total detection rate of PAHs in groundwater of the coking plant was 46.7%. The concentrations of PAHs in groundwater of the coking plant ranged from below the detection limit to 444.9 µg·L-1, with the average value of 1.88 µg·L-1. The concentration of PAHs in the groundwater of different production workshops was significantly different. The most polluted workshop was in the tar-refining area, and the concentration of 16 PAHs was 444.9 µg·L-1. Based on the PMF model, we identified the two primary contamination sources of PAHs in groundwater of the coking plant:① oil combustion and ② coal and biomass combustion and oil leakage. The contribution ratios of the two sources to PAHs of groundwater were 38.6% and 61.4%, respectively. The results of the ecological risk assessment indicated that Σ16PAHs in groundwater of the coking plant had high ecological risk, and the ecological risk of single PAHs in 53.4% of the groundwater sampling site was at a high ecological risk level. In conclusion, it is urgent to carry out the treatment and restoration of the groundwater environment in the coking plant site.

Odorant-Binding Protein HvarOBP5 in Ladybird Hippodamia variegata Regulates the Perception of Semiochemicals from Preys and Habitat Plants.

A total of 12 OBPs were identified in the antennae of ladybird Hippodamia variegata. HvarOBP1/2/5/6/10/11 were highly expressed in adults, whereas HvarOBP3/4/7/8/9/12 had higher expression levels in larvae. In adults, HvarOBP1/2/4/5/6/7/8/11/12 were highly expressed in antennae. Among these, recombinant HvarOBP5 strong bound with (E)-ß-farnesene (EßF), (R)-(+)-limonene, (E,E)-4,8,12-trimethyltrideca-l,3,7,11-tetraene (TMTT), (E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), hexyl hexanoate, and geranyl acetate. Molecular docking indicated that Leu42, Lys43, and His64 were the key binding sites of HvarOBP5. All six ligands evoked electroantennography (EAG) responses in ladybirds. Moreover, (R)-(+)-limonene and hexyl hexanoate were attractive to both sexes. After RNA interference for 72 h, the EAGs of dsRNA-injected ladybirds to DMNT and hexyl hexanoate were significantly decreased by 73.8 and 78.6%, respectively. Both dsRNA-injected males and females showed significantly lower behavioral preferences for DMNT and hexyl hexanoate. These findings suggest that HvarOBP5 in H. variegata plays an important role in the perception of semiochemical cues from preys and habitat plants.

Amygdala Metabotropic Glutamate Receptor 1 Influences Synaptic Transmission to Participate in Fentanyl-Induced Hyperalgesia in Rats.

The underlying mechanisms of opioid-induced hyperalgesia (OIH) remain unclear. Herein, we found that the protein expression of metabotropic glutamate receptor 1 (mGluR1) was significantly increased in the right but not in the left laterocapsular division of central nucleus of the amygdala (CeLC) in OIH rats. In CeLC neurons, the frequency and the amplitude of mini-excitatory postsynaptic currents (mEPSCs) were significantly increased in fentanyl group which were decreased by acute application of a mGluR1 antagonist, A841720. Finally, the behavioral hypersensitivity could be reversed by A841720 microinjection into the right CeLC. These results show that the right CeLC mGluR1 is an important factor associated with OIH that enhances synaptic transmission and could be a potential drug target to alleviate fentanyl-induced hyperalgesia.

Quantitative identification of groundwater contamination sources by combining isotope tracer technique with PMF model in an arid area of northwestern China.

Nowadays, groundwater quality has deteriorated because of intensive human activities. It is important to accurately identify the pollution source for controlling the deterioration of groundwater quality. However, the accuracy of the current source analysis method needs to be improved. In this study, we combined hydrochemical method, isotope tracing technique and PMF model, for the first time, to trace the source of groundwater pollution in Beichuan River basin, Qinghai Province, China. According to the results, there were 35.8% of Fe, 34.1% of total hardness, 24.3% of SO42- and 8.09% of NO3- samples exceeded the Grade III standards for Groundwater quality in China, which indicated that the groundwater in the study area has been significantly affected by human activities. Hydrochemical method suggested that the chemical component originated from rock weathering, cation exchange and mineral dissolution. Based on isotope tracing technique (δ15N-NO3-, δ18O-NO3-, δ34S-SO42- and δ18O-SO42-), the primary sources of nitrate and sulfate in groundwater were soil nitrogen and oxidation of sulfide minerals in the forest area, domestic sewage and oxidation of sulfide minerals in the urban and industrial area, and mixed sources in the village and agricultural area. Finally, the pollution source of groundwater was distinguished by combining the PMF model, isotope tracing technique and hydrochemical method. Results showed that the main pollutant of groundwater is domestic sewage in the urban, village and industrial area. The contribution rates to groundwater pollution were 60.7%, 60.8% and 57.8%, respectively. However, in the forest and agricultural area, the main source changed to water-rock interaction and chemical fertilizer, and the contribution rates to groundwater quality were 53.5% and 61.0%, respectively. Our results suggested that the coupling tracing methodology can improve the accuracy of source resolution in the water environment and it can be applied to other areas of the world.

Primary Alveolar Soft-Part Sarcoma of the Lung: A Case Report.

Alveolar soft-part sarcoma is a rare type of soft tissue malignant tumor. Although the tumor can occur in many parts of the body, primary alveolar soft-part sarcoma of the lung is extremely rare. According to previous literature, only 3 cases of primary alveolar soft-part sarcoma of the lung were reported, and no comprehensive analysis was conducted on these cases. Here, we describe another case of alveolar soft-part sarcoma in the lung, where the negative results of immunohistochemical staining cause extreme difficulty in distinguishing this lesion from other tumors. A 30-year-old Chinese male presented with chest pain and dyspnea. Computed tomography revealed a pulmonary mass, and biopsy results showed vacuolar tumor cells with abundant eosinophilic cytoplasm. A number of immunohistochemical markers were negative, but the tumor cells were positive for TFE3 and ASPSCR1::TFE3 fusion gene. No other tumor masses were found in the patient after whole-body scanning. The final diagnosis was primary alveolar soft-part sarcoma of the lung. Pathologists should consider the possibility of alveolar soft-part sarcoma in lung tumors with typical "organ like" or "acinar like" cell nests, where the tumor cells are large, vacuolated, and the nucleolus is obvious. After excluding metastasis from other sites, TFE3 immunohistochemical staining and ASPSCR1::TFE3 fusion gene detection are recommended for the diagnosis of primary alveolar soft-part sarcoma.

Optical variations of dissolved organic matter due to surface water - groundwater interaction in alpine and arid Datonghe watershed.

The direction and quantity of surface water - groundwater interaction (SGI) in alpine-arid zones can be tracked using multiple tracers. However, few studies have examined whether the optical indices of dissolved organic matter (DOM) can also track SGI. This study used excitation-emission matrix spectroscopy combined with parallel factor analysis (EEM-PARAFAC) to reveal the optical variations in dissolved organic matter (DOM) in groundwater and surface water with various SGIs in the Datonghe watershed. The results showed that the absorbance spectral indices of DOM did not vary with SGI, whereas DOM fluorescence varied with SGI. PARAFAC indicated that groundwater predominantly recharged by precipitation had significantly lower humic-like (C2 and C3) fluorescence than groundwater predominantly recharged by riverine water. Since humic-like substances were more likely to be retained in the aqueous phase than protein-like substances, significantly fewer protein-like substances (C4) were introduced when surface water was recharged to groundwater. This suggests that C4 can be used as an effective indicator to identify the SGI process from surface water to groundwater. Based on the principal component analysis of DOM and hydrochemical indicators, it was concluded that traditional chemical tracers were significantly and positively correlated with humic-like substances C2 and C3. Given that C3 is more stable and persistent in the environment, it could be used to track SGI processes midstream of the watershed. The findings of this study will assist in accurately identifying the processes and mechanisms of SGI on a regional scale and provide a basis for future water resource management and the protection of water ecosystems.

Calcium Channel α2δ1 is Essential for Pancreatic Tumor-Initiating Cells through Sequential Phosphorylation of PKM2.

BACKGROUND & AIMS: Tumor-initiating cells (TICs) drive pancreatic cancer tumorigenesis, therapeutic resistance, and metastasis. However, TICs are highly plastic and heterogenous, which impede the robust identification and targeted therapy of such a population. The aim of this study is to identify the surface marker and therapeutic target for pancreatic TICs. METHODS: We isolated voltage-gated calcium channel α2δ1 subunit (isoform 5)-positive subpopulation from pancreatic cancer cell lines and freshly resected primary tissues by fluorescence-activated cell sorting and evaluated their TIC properties by spheroid formation and tumorigenic assays. Coimmunoprecipitation was used to identify the direct substrate of CaMKⅡδ. RESULTS: We demonstrate that the voltage-gated calcium channel α2δ1 subunit (isoform 5) marks a subpopulation of pancreatic TICs with the highest TIC frequency among the known pancreatic TIC markers tested. Furthermore, α2δ1 is functionally sufficient and indispensable to promote TIC properties by mediating Ca2+ influx, which activates CaMKⅡδ to directly phosphorylate PKM2 at T454 that results in subsequent phosphorylation at Y105 to translocate into nucleus, enhancing the stem-like properties. Interestingly, blocking α2δ1 with its specific antibody has remarkably therapeutic effects on pancreatic cancer xenografts by reducing TICs. CONCLUSIONS: α2δ1 promotes pancreatic TIC properties through sequential phosphorylation of PKM2 mediated by CaMKⅡδ, and targeting α2δ1 provides a therapeutic strategy against TICs for pancreatic cancer.

Contrasting diversity patterns and community assembly mechanisms of bacterioplankton among different aquatic habitats in Lake Taihu, a large eutrophic shallow lake in China.

Eutrophication leads to the degradation of lake habitat types from macrophyte-dominated habitats (MDH) to algae-dominated habitats (ADH), which is a common environmental problem faced by many lakes. However, the variations in diversities and community assembly processes of bacterioplankton in the process of lake eutrophication have not been thoroughly elucidated. Here, we contrasted bacterial diversity patterns and processes of community assembly among ADH, MDH, and other habitats (OH) of Lake Taihu, a large shallow eutrophic lake in China with strong wind-induced disturbances. We found that the bacterial diversity patterns and potential functions between ADH and MDH were significantly different. Moreover, the contributions of purely environmental variables to the bacterial diversity patterns of all habitat types were much higher than those of spatial variables. However, the relative importance of stochasticity in the bacterial community assembly of each habitat type was much higher than that of determinism. Intriguingly, 'undominated' stochastic processes shape the diversity patterns of bacterioplankton in ADH, MDH, and OH of Lake Taihu. These findings demonstrate that the degradation of lake habitats caused by eutrophication can profoundly change the diversity and potential function patterns of the bacterioplankton community in lake ecosystems. Although the distinct diversity patterns of the bacterioplankton among the different aquatic habitats in Lake Taihu can be affected by deterministic processes (local environmental variables), they were dominated by stochastic processes (drift). Our study confirms that strong, disordered, wind-induced disturbances in shallow lakes could lead to strong hydrologic mixing, thus increasing the randomness of bacterial community assembly in each habitat.

[Characteristics and Causes of High-manganese Groundwater in Pearl River Delta During Urbanization].

The high concentration of iron and manganese in groundwater is harmful to human health, and the sources of manganese in rapidly urbanization areas are complex. Based on more than 2500 sets of hydrochemical data in different historical periods, the spatial distribution characteristics, sources, and genesis of groundwater manganese in different aquifers and areas with different urbanization levels in the Pearl River Delta were studied by using mathematical statistics and principal component analysis. The results showed that the concentration of manganese in groundwater in the pore aquifer was obviously higher than that in the fissure and karst aquifer. The proportion of high-manganese groundwater in the pore aquifer was twice that in the fissure and karst aquifer. The proportion of high-manganese groundwater in urbanized and suburban areas was significantly higher than that in non-urbanized areas. On a regional scale, the decomposition of organic matter and the reductive dissolution of Fe-Mn (oxygen) hydroxide in sedimentary strata under reductive conditions may have been the main factors controlling the increase in manganese concentration in pore aquifers. High-manganese groundwater in fissured aquifers may have been affected by low-oxygen domestic sewage leakage accompanying urbanization and industrial wastewater leakage and infiltration accompanying industrialization. The pore high-manganese groundwater was controlled by reduction conditions, and the weakly acidic environment of fissure and karst high-manganese groundwater was the important influencing factor. In the past 10 years, the groundwater environment in the study area has been improving, and the increase in groundwater redox potential and pH was not conducive to the formation of high-manganese groundwater, which was also the main cause of the overall decrease in Mn2+ concentration in groundwater of different types of aquifers in the process of urbanization.

Characteristics and mechanisms of resorption in lumbar disc herniation.

Lumbar disc herniation (LDH) can be spontaneously absorbed without surgical treatment. However, the pathogenesis and physiological indications for predicting protrusion reabsorption are still unclear, which prevents clinicians from preferentially choosing conservative treatment options for LDH patients with reabsorption effects. The purpose of this review was to summarize previous reports on LDH reabsorption and to discuss the clinical and imaging features that favor natural absorption. We highlighted the biological mechanisms involved in the phenomenon of LDH reabsorption, including macrophage infiltration, inflammatory responses, matrix remodeling, and neovascularization. In addition, we summarized and discussed potential clinical treatments for promoting reabsorption. Current evidence suggests that macrophage regulation of inflammatory mediators, matrix metalloproteinases, and specific cytokines in intervertebral disc is essential for the spontaneous reabsorption of LDH.

Water Uptake Tradeoffs of Dominant Shrub Species in the Coastal Wetlands of the Yellow River Delta, China.

Tamarix chinensis and Ziziphus jujuba are two dominant shrub species on Chenier Island in the Yellow River Delta, China. Water is a restrictive factor determining the plant growth, vegetation composition, and community succession in this coastal zone. We investigated how water uptake tradeoffs of the two shrub species responded to soil water fluctuations caused by seasonal variations of precipitation. The soil water content, salinity and δ18O values of potential water sources (soil water in 0-20, 20-40, 40-60, and 60-100 cm soil layers, and groundwater) and plant xylem water were measured in wet (July 2013) and dry (July 2014) seasons. The IsoSource model was employed to calculate the contributions of different water sources to plant xylem water. The results showed that δ18O values of soil water decreased significantly with soil depth in the dry season, while increased significantly with soil depth in the wet season. In the wet season, when the soil water was abundant, Z. jujuba mostly used the soil water from the 60-100 cm layer, while T. chinensis took up a mixture of groundwater and soil water from the 60-100 cm layer. In the dry season, when the soil water was depleted because of low precipitation, Z. jujuba mainly took up a mixture of the soil water from 20 to 100 cm soil layers, while T. chinensis mainly used groundwater. T. chinensis and Z. jujuba showed different ecological amplitudes of water sources during dry and wet seasons. The niche differentiation of major water sources for T. chinensis and Z. jujuba demonstrated their adaptabilities to the fluctuations of soil moisture in water-limited ecosystems. Water niche differentiations of coexisting shrub species were expected to minimize their competition for limited water sources, contributing to successful coexistence and increasing the resilience of the coastal wetland ecosystem to drought.

Rising Shallow Groundwater Level May Facilitate Seed Persistence in the Supratidal Wetlands of the Yellow River Delta.

The saline groundwater level of many supratidal wetlands is rising, which is expected to continue into the future because of sea level rise by the changing climate. Plant persistence strategies are increasingly important in the face of changing climate. However, the response of seed persistence to increasing groundwater level and salinity conditions is poorly understood despite its importance for the continuous regeneration of plant populations. Here, we determined the initial seed germinability and viability of seven species from supratidal wetlands in the Yellow River Delta and then stored the seeds for 90 days. The storage treatments consisted of two factors: groundwater level (to maintain moist and saturated conditions) and groundwater salinity (0, 10, 20, and 30 g/L). After retrieval from experimental storage, seed persistence was assessed. We verified that the annuals showed greater seed persistence than the perennials in the supratidal wetlands. Overall, seed persistence was greater after storage in saturated conditions than moist conditions. Salinity positively affected seed persistence under moist conditions. Surprisingly, we also found that higher groundwater salinity was associated with faster germination speed after storage. These results indicate that, once dispersed into habitats with high groundwater levels and high groundwater salinity in supratidal wetlands, many species of seeds may not germinate but maintain viability for some amount of time to respond to climate change.