Bioinformatic Analysis of m6A Regulator-Mediated RNA Methylation Modification Patterns and Immune Microenvironment Characterization in Endometriosis.

Epigenetic regulation plays an essential role in immunity and inflammation in endometriosis. In this study, we aimed to explore differences in m6A regulators between endometriosis patients and normal women and analyze the effect of m6A modification on immune and inflammatory microenvironment. The samples for analysis were downloaded from the Gene Expression Omnibus database, including ectopic endometrium (EC), eutopic endometrium (EU), and normal eutopic endometrium (NM) samples from non-endometriosis women. The validation process involved utilizing our previous RNA-sequencing data. Subsequently, a correlation analysis was performed to ascertain the relationship between m6A and the inflammatory microenvironment profile, encompassing infiltrating immunocytes, immune-inflammation reaction gene sets, and human leukocyte antigen genes. LASSO analyses were used to develop risk signature. The findings of this study indicate that the m6A regulators FTO were observed to be significantly up-regulated, while YTHDF2, CBLL1, and METTL3 were down-regulated in endometriosis tissues. The CIBERSORT analysis revealed that the local inflammatory microenvironment of ectopic lesions plays a crucial role in the development of endometriosis. Notably, M2 macrophages exhibited a significant difference between the EC and NM groups. Moreover, M2 macrophages demonstrated a positive correlation with FTO (0.39) and a negative correlation with CBLL1 (- 0.35). Furthermore, consistent clustering of EC and EU samples resulted in the identification of three distinct cell subtypes. Among different cell subtypes, significant differences were in immunoinfiltrating cells, plasma cells, naive CD4 T cells, memory activated CD4 T cells, gamma delta T cells, resting NK cells and activated NK cells but not in macrophages. Furthermore, the identification of various compounds capable of targeting these m6A genes was achieved. In conclusions, our integrated bioinformatics analysis results demonstrated that m6A-related genes METTL3, CBLL1 and YTHDF2 may be useful biomarkers for endometriosis in ectopic endometrium. The potential therapeutic approach of targeting m6A regulators holds promise for the treatment of endometriosis.

Electroacupuncture Improves Depression-Like Behavior by Regulating the Abundance of Lactobacillus and Staphylococci in Mice.

BACKGROUND: Growing evidence suggests that gut microbiota can affect depression-like behavior, and electroacupuncture (EA) can regulate the composition and abundance of gut microbiota. At the same time, not a lot of research has been done on how EA affects gut microbiota to depression-like behavior. The objective of this study was to study the associated mechanisms by which EA exerts antidepressant effects by modulating gut microbiota. METHODS: Twenty-four C57BL/6 male mice were randomly divided into three groups, one group (n = 8) was the normal control group (NC). And the other two groups was chronic unpredictable mild stress for modeling + electroacupuncture group (CUMS + EA) (n = 8) and chronic unpredictable mild stress for modeling group (CUMS) (n = 8). Both CUMS and EA groups were subjected to 28 days of CUMS, but only the EA group received an additional 14 days of EA procedure. Behavior tests were used to determine the antidepressant effect of EA. Sequencing of the 16S ribosomal RNA (rRNA) gene was applied to examine alterations in the intestinal microbiome between groups. RESULTS: The findings were compared to those of the NC group, the sucrose preference rate and the total distance of Open Field Test (OFT) in CUMS group decreased, the abundance of Lactobacillus decreased, while the abundance of staphylococci increased. After the intervention of EA, the sucrose preference index and the total distance of OFT increased, the abundance of Lactobacillus increased, while the abundance of staphylococci decreased. CONCLUSIONS: These findings indicated EA may play an antidepressant effect by adjusting the abundance of Lactobacillus and staphylococci.

EA Ameliorated Depressive Behaviors in CUMS Rats and Was Related to Its Suppressing Autophagy in the Hippocampus.

Autophagy is confirmed to be involved in the onset and development of depression, and some antidepressants took effect by influencing the autophagic process. Electroacupuncture (EA), as a common complementary treatment for depression, may share the mechanism of influencing autophagy in the hippocampus like antidepressants. To investigate that, sixty Sprague-Dawley rats firstly went through chronic unpredictable mild stress (CUMS) model establishment, and 15 rats were assigned to a control group. After modeling, 45 successfully CUMS-induced rats were randomly divided to 3 groups: CUMS, selective serotonin reuptake inhibitor (SSRI), and EA groups (15 rats per group), to accept different interventions for 2 weeks. A sucrose preference test (SPT), weighing, and open field test (OFT) were measurement for depressive behaviors of rats. Transmission electron microscope (TEM), immunohistochemistry (IHC), and western blot analysis were used to evaluate the autophagic changes. After that, depression-like behaviors were successfully induced in CUMS models and reversed by SSRI and EA treatments (both p < 0.05), but these two therapies had nonsignificant difference between each other (p > 0.05). Autolysosomes observed through TEM in the CUMS group were more than that in the control group. Their number and size in the SSRI and EA groups also decreased significantly. From IHC, the CUMS group showed enhanced positive expression of both Beclin1 and LC3 in CA1 after modeling (p < 0.05), and the LC3 level declined after EA treatments, which was verified by decreased LC3-II/LC3-I in western blot analysis. We speculated that CUMS-induced depression-like behavior was interacted with an autophagy process in the hippocampus, and EA demonstrated antidepressant effects by partly inhibiting autophagy with a decreased number of autolysosomes and level of LC3 along with LC3-II/LC3-I.

Spatio-temporal variation and source changes of potentially toxic elements in soil on a typical plain of the Yangtze River Delta, China (2002-2012).

The spatio-temporal variation and temporal changes in the sources of Cr, Pb, Cd, Hg, and As in soil on the Hangzhou-Jiaxing-Huzhou (H-J-H) Plain were analysed based on 4,359 soil samples collected in 2002 and 2012. Geostatistical and spatial analysis methods were used to explore the spatio-temporal variation in the pollution levels and 'pollution hotspots' for potentially toxic elements (PTEs), and the positive matrix factor model was used to quantitatively appoint and analyse temporal changes in PTE sources. The results indicated that the PTE content in most parts of the survey area were at a safe level in both 2002 and 2012, but a clearly upward trend was detected for Cr, Pb, and Cd. Moreover the pollution index for Cr, Pb, Cd, and the Nemerow composite pollution index increased in the west but decreased in the east of the H-J-H Plain from 2002 to 2012. The pollution index for Hg and As presented the opposite spatial pattern. It is obvious that there have been changes in the spatial pattern of pollution hotspots for PTEs on the H-J-H Plain from 2002 to 2012. Four sources of PTEs in soil were quantitatively appointed. In 2002, 2012, the dominant sources of Cr, Cd, Hg, and As were soil parent materials, industrial activities, atmospheric deposition and agricultural inputs, respectively. The dominant source of Pb in the soil changed from traffic emissions to soil parent materials, indicating the benefit of banning the use of leaded gasoline in China. This study highlights the importance of monitoring soil environmental quality and highlights the significance of spatio-temporal variation in PTEs in suburban zones or transitional areas undergoing rapid industrialization and urbanization, like the H-J-H Plain.

Differential Expression of Tubulin Acetylase and Deacetylase Between the Damaged Central and Peripheral Branch of Dorsal Root Ganglion Neurons.

BACKGROUND The differences between the peripheral and central branches of the dorsal root ganglion (DRG) have not been fully elucidated. This study aimed to explore the expression of tubulin post-translational modifications (acetylation and deacetylation) between damaged peripheral and central branches of DRG neurons. MATERIAL AND METHODS Fifty Sprague-Dawley rats were randomly assigned to five groups with 10 rats in each group. These five groups consisted of spinal nerve ligation (SNL) at 24 hour and 48 hour, and cauda equina compression (CEC) at 24 hour and 48 hour, and a sham group. SNL injury in rats was induced by ligating L5 and L6 spinal nerves with 1-0 silk thread outboard the DRGs. CEC injury in rats was induced by a piece of silicone (10×1×1 mm) placed under the laminae of the L5-6 vertebra. Sham-operated rats underwent a simple laminectomy in L4, but silicone was not implanted. The expression profile of acetylase and deacetylase was examined by real-time PCR, Western blotting, and immunohistochemistry. RESULTS In the experimental groups, rats presented increased expression of acetylase (NAT1 and MEC-17) and decreased expression of deacetylase (Sirt2 and HDAC6) levels. Additionally, the expression of NAT1 and MEC-17 was gradually increased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. Conversely, the expression of Sirt2 and HDAC6 was gradually decreased in DRG neurons following peripheral axonal injury compared to central axonal injury in a time-dependent manner. CONCLUSIONS Our study indicated that insufficiency of acetylase and upregulation of deacetylase in DRG neurons after central axonal injury may contribute to the pathogenesis of cauda equine syndrome.

Integration of 16 S rRNA gene sequencing, metabonomics and metagenome analysis to investigate the mechanism of Sparganium stoloniferum-Curcuma phaeocaulis in treating of endometriosis in rats.

BACKGROUND: Endometriosis is a gynecological disease that causes severe chronic pelvic pain and infertility in women. The therapeutic efficacy of the traditional herbal combination of Sparganium stoloniferum-Curcuma phaeocaulis (Sangleng-Ezhu, SL-EZ) in the treatment of endometriosis has been established. However, the precise mechanism by which this treatment exerts its effects remains elusive. METHODS: To gain further insights, UPLC-MS/MS was employed to identify the primary chemical constituents of SL-EZ in serum. Additionally, network pharmacology was utilized to analyze the active ingredients and their corresponding targets. Furthermore, the impact of SL-EZ on ectopic endometrial growth in endometrial implants was assessed using a rat model. The therapeutic mechanism of SL-EZ in rats with endometriosis was further investigated through the application of 16 S rRNA gene sequencing, metagenomic sequencing, and metabolomics. RESULTS: The primary compounds in serum were zederone, p-coumaric acid, dehydrocostus lactone, curdione, curcumol. The growth of ectopic lesions in a rat model was effectively inhibited by SL-EZ. In comparison to the control group, the endometriotic rats exhibited a decrease in α-diversity of the gut microbiota, an increase in the Firmicutes/Bacteroidetes ratio, and a reduction in the abundance of Ruminococcaceae. Following SL-EZ intervention, the potential probiotic strains Lactobacillus gasseri and Lactobacillus johnsonii were able to restore the intestinal microenvironment at the species level. The altered metabolites were significantly correlated with Verrucomicrobia, Proteobacteria, and Bacteroidetes. The metabolomic analysis demonstrated significant alterations in intestinal metabolites. And SL-EZ intervention also exerted regulatory effects on various metabolic pathways in gut microbiota, including aminoacyl-tRNA biosynthesis, monobactam biosynthesis, cyanoamino acid metabolism, glycine, serine and threonine metabolism, plant secondary metabolite biosynthesis, and amino acid biosynthesis. CONCLUSION: The identification of novel treatment formulations for endometriosis was achieved through the utilization of network pharmacology and gut microbiota analyses. Our findings revealed simultaneous alterations in the microbiota within the rat model of endometriosis. The therapeutic efficacy of SL-EZ in treating endometriosis is attributed to its ability to restore the gut microbiota and regulate metabolism. This investigation offers valuable insights into the therapeutic mechanisms of traditional Chinese medicine (TCM) for endometriosis.

Increased miR-195 aggravates neuropathic pain by inhibiting autophagy following peripheral nerve injury.

UNLABELLED: Following peripheral nerve injury (PNI) microglia proliferates and adopts inflammation that contributes to development and maintenance of neuropathic pain. miRNAs and autophagy are two important factors in the regulation of inflammation. However, little is known about whether miRNAs regulate neuroinflammation and neuropathic pain by controlling autophagy. In the study, we demonstrated that miR-195 levels were markedly increased in rats subjected to L5 spinal nerve ligation (SNL). Upregulated miR-195 was also found in spinal microglia of rats with SNL. The overexpression of miR-195 contributed to lipopolysaccharide-induced expression of proinflammatory cytokines IL-1ß, TNF-α, and iNOS in cultured microglia. Upregulated miR-195 also resulted in increased mechanical and cold hypersensitivity after PNI, whereas miR-195 inhibition reduced mechanical and cold sensitivity. We further demonstrated that PNI significantly inhibited microglial autophagy activation, whereas miR-195 inhibitor treatment increased autophagy activation and suppressed neuroinflammation in vivo and in vitro. More important, autophagy inhibition impaired miR-195 inhibitor-induced downregulation of neuroinflammation and neuropathic pain. Additionally, ATG14 was identified as the functional target of miR-195. CONCLUSIONS: These data demonstrated that miR-195/autophagy signaling represents a novel pathway regulating neuroinflammation and neuropathic pain, thus offering a new target for therapy of neuropathic pain.

QTL mapping of stalk bending strength in a recombinant inbred line maize population.

Stalk bending strength (SBS) is a reliable indicator for evaluating stalk lodging resistance of maize plants. Based on biomechanical considerations, the maximum load exerted to breaking (F max), the breaking moment (M max) and critical stress (σ max) are three important parameters to characterize SBS. We investigated the genetic architecture of SBS by phenotyping F max, M max and σ max of the fourth internode of maize plants in a population of 216 recombinant inbred lines derived from the cross B73 × Ce03005 evaluated in four environments. Heritability of F max, M max and σ max was 0.81, 0.79 and 0.75, respectively. F max and σ max were positively correlated with several other stalk characters. By using a linkage map with 129 SSR markers, we detected two, three and two quantitative trait loci (QTL) explaining 22.4, 26.1 and 17.2 % of the genotypic variance for F max, M max and σ max, respectively. The QTL for F max, M max and σ max located in adjacent bins 5.02 and 5.03 as well as in bin 10.04 for F max were detected with high frequencies in cross-validation. As our QTL mapping results suggested a complex polygenic inheritance for SBS-related traits, we also evaluated the prediction accuracy of two genomic prediction methods (GBLUP and BayesB). In general, we found that both explained considerably higher proportions of the genetic variance than the values obtained in QTL mapping with cross-validation. Nevertheless, the identified QTL regions could be used as a starting point for fine mapping and gene cloning.

Effects of Different Intervertebral Space Heights on Nerve Root Tension during Posterior Lumbar Interbody Fusion.

OBJECTIVE: There is no effective standard method to evaluate whether the nerve root tension is restored during lumbar decompression surgery, which is an important indicator for the recovery of nerve function. This study aimed to investigate the feasibility of intraoperative nerve root tension measurement and to confirm the correlation between nerve root tension and intervertebral space height. METHODS: A total of 54 consecutive patients (mean age, 54.3 years; range, 25-68 years) received posterior lumbar interbody fusion (PLIF) for lumbar disc herniation (LDH) with lumbar spinal stenosis and instability. The 110%, 120%, 130%, 140% height values of each lesion were calculated based on preoperative measurements of the intervertebral space height. The heights were intraoperatively expanded after the intervertebral disc was removed using the interbody fusion cage model. The tension value of nerve root was measured by pulling the nerve root for 5 mm with a self-made measuring device. The nerve root tension value was measured before decompression, after discectomy at 100%, 110%, 120%, 130%, and 140% of the height of each intervertebral space, and after placement of the cage during intraoperative nerve root tension monitoring. RESULTS: The nerve root tension values at 100%, 110%, 120%, and 130% heights were significantly lower than those before decompression, and there was no statistical significance among the four groups. The nerve root tension value was significantly higher at 140% height and was statistically significant compared with that of 130% height. The nerve root tension value after cage placement was significantly lower than that before decompression (1.32 ± 0.22 N vs. 0.61 ± 0.17 N, p < 0.01), and the postoperative VAS score was also significantly improved (7.0 ± 2.24 vs. 0.8 ± 0.84, p < 0.01). The nerve root tension was positively correlated with the VAS score (F = 85.19, p < 0.01; F = 78.65, p < 0.01). CONCLUSION: This study demonstrates that nerve root tonometry can perform instant noninvasive intraoperative nerve root tension measurement. There is a correlation between nerve root tension value and VAS score. We found that when the height of the intervertebral space was increased to 140% of the original height, the nerve root tension increased the risk of injury significantly.

BNTA alleviates inflammatory osteolysis by the SOD mediated anti-oxidation and anti-inflammation effect on inhibiting osteoclastogenesis.

Abnormal activation and overproliferation of osteoclast in inflammatory bone diseases lead to osteolysis and bone mass loss. Although current pharmacological treatments have made extensive advances, limitations still exist. N-[2-bromo-4-(phenylsulfonyl)-3-thienyl]-2-chlorobenzamide (BNTA) is an artificially synthesized molecule compound that has antioxidant and anti-inflammatory properties. In this study, we presented that BNTA can suppress intracellular ROS levels through increasing ROS scavenging enzymes SOD1 and SOD2, subsequently attenuating the MARK signaling pathway and the transcription of NFATc1, leading to the inhibition of osteoclast formation and osteolytic resorption. Moreover, the results also showed an obvious restrained effect of BNTA on RANKL-stimulated proinflammatory cytokines, which indirectly mediated osteoclastogenesis. In line with the in vitro results, BNTA protected LPS-induced severe bone loss in vivo by enhancing scavenging enzymes, reducing proinflammatory cytokines, and decreasing osteoclast formation. Taken together, all of the results demonstrate that BNTA effectively represses oxidation, regulates inflammatory activity, and inhibits osteolytic bone resorption, and it may be a potential and exploitable drug to prevent inflammatory osteolytic bone diseases.

Anatomical Evaluation of Spinal Nerve and Cervical Intervertebral Foramina in Anterior Controllable Antedisplacement and Fusion Surgery: A Cadaveric and Radiologic Study.

OBJECTIVE: To achieve the anatomical evaluation of spinal nerve and cervical intervertebral foramina in anterior controllable antedisplacement and fusion (ACAF) surgery, a novel surgical technique with the wider decompression, through a cadaveric and radiologic study. METHODS: Radiographic data of consecutive 47 patients (21 by ACAF and 26 by anterior cervical corpectomy and fusion [ACCF]) who have accepted surgery for treatment of cervical ossification of the posterior longitudinal ligament(OPLL) and stenosis from March 2017 to March 2018 were retrospectively reviewed and compared between an ACAF group and ACCF group. Three postoperative radiographic parameters were evaluated: the decompression width and the satisfaction rate of decompression at the entrance zone of intervertebral foramina on computed tomography (CT), and the transverse diameter of spinal cord in the decompression levels on magnetic resonance imaging (MRI). In the anatomic study, three fresh cadaveric spines (death within 3 months) undergoing ACAF surgery were also studied. Four anatomic parameters were evaluated: the width of groove, the distance between the bilateral origins of ventral rootlets, the length of ventral rootlet from their origin to the intervertebral foramina, the descending angle of ventral rootlet. RESULTS: The groove created in ACAF surgery included the bilateral origins of ventral rootlets. The rootlets tended to be vertical from the rostral to the caudal direction as their takeoff points from the central thecal sac became higher and farther away from their corresponding intervertebral foramina gradually. No differences were identified between left and right in terms of the length of ventral rootlet from the origin to the intervertebral foramina and the descending angle of ventral rootlet. The decompression width was significantly greater in ACAF group (19.2 ± 1.2 vs 14.7 ± 1.2, 21.3 ± 2.2 vs 15.4 ± 0.9, 21.5 ± 2.1 vs 15.7 ± 1.0, 21.9 ± 1.6 vs 15.9 ± 0.8, from C3 to C6 ). The satisfactory rate of decompression at the entrance zone of intervertebral foramina tended to be better in the left side in ACAF group (significant differences were identified in the left side at C3/4 , C4/5 , C6/7 level, and in the right side at C4/5 level when compared with ACCF). And decompression width was significantly greater than the transverse diameter of spinal cord in ACAF group. Comparatively, there existed no significant difference in the ACCF group besides the C5 level. CONCLUSION: ACAF can decompress the entrance zone of intervertebral foramina effectively and its decompression width includes the origins and massive running part of bilateral ventral rootlets. Due to its wider decompression range, ACAF can be used as a revision strategy for the patients with failed ACCF.

Selections of Bone Cement Viscosity and Volume in Percutaneous Vertebroplasty: A Retrospective Cohort Study.

OBJECTIVE: We sought to evaluate the efficacy and complications of percutaneous vertebroplasty with different viscosities and volumes of bone cement in treating osteoporotic vertebral compression fractures (OVCFs). METHOD: We conducted a retrospective cohort study of 307 patients treated for a single thoracolumbar level (T12-L2) OVCF in our hospital between January 2014 and December 2019. The patients were divided into 6 groups according to different viscosities (I: low-viscosity bone cement, II: high-viscosity bone cement) and injection volumes (A, 2-4 mL; B, 4-6 mL; C, 6-8 mL) of bone cement. Clinical and radiologic characteristics including visual analog scale, local kyphotic angle, anterior vertebral height ratio, cement leakage, and vertebral body recollapse rate were collected preoperatively, 2 days postoperation, and at the last follow-up to assess the efficacy and complications of each group. RESULTS: Regarding efficacy, there was no significant difference between the 2 kinds of bone cement. Injecting >4 mL of cement can provide patients with good improvements of clinical indicators and a low vertebral body recollapse rate. Injecting 6-8 mL of bone cement slightly improved the radiologic indicators. However, the leakage rate of low-viscosity bone cement increased significantly when the volume exceeded 6 mL. The leakage rate of high-viscosity bone cement did not increase significantly at the volume of 6-8 mL. CONCLUSIONS: In summary, when treating single thoracolumbar level OVCFs, the recommended volume of low-viscosity bone cement is 4-6 mL while the optimal volume of high-viscosity bone cement is 6-8 mL.

Assessment of potentially toxic element pollution in soils and related health risks in 271 cities across China.

Potentially toxic element (PTE) pollution has been extensively studied at a local and regional scale in China. However, further research needs to be conducted at a national level. To this end, in current study we systematically compiled data of around 170,000 soil samples collected from 1153 papers published between 2008 and 2018. Based on these data we conducted a comprehensive analysis on the pollution status, pollution hotspots, and potential dominant sources of PTEs (As, Cd, Cr, Cu, Hg, Pb, Ni and Zn) in soils in 271 cities of China using geochemical accumulation index, potential ecological risk index, health risk evaluation model, univariate local Moran's I index, and bivariate local Moran's I index. Our results indicated an obvious accumulation of PTEs in the soils of most cities. In addition, the contents of Cd, Hg, Pb, and Ni were higher in China when compared to other several countries under comparison. Pollution hotspots of PTE and hotspots of human health risks may occur due to PTE exposure were mainly distributed in South (S) and Southwest (SW) of China. Cities with PTEs accumulation in soil due to industrial activities were mainly located in East (E) and North (N) China. Cities that had high concentrations of PTE due to agricultural activities were mainly located in central and Northeast (NE) China. Most cities with an accumulation of PTEs in soils primarily due to mining activities were found in West (W) and Northwest (N) China. Cities with PTEs mainly sourced from soil parental material were distributed in Southwest (SW) China. This study provides comprehensive and specific information and valuable implications for developing advanced scientific and efficient strategies to prevent and control PTE pollution the soils in China.

Transplantation of neural stem cells encapsulated in hydrogels improve functional recovery in a cauda equina lesion model.

This study explored the therapeutic effects of transplantation of neural stem cells (NSCs) encapsulated in hydrogels in a cauda equina lesion model. NSCs were isolated from neonatal dorsal root ganglion (nDRG) and cultured in three-dimensional porous hydrogel scaffolds. Immunohistochemistry, transmission electron microscopy and TUNEL assay were performed to detect the differentiation capability, ultrastructural and pathological changes, and apoptosis of NSCs. Furthermore, the functional recovery of sensorimotor reflexes was determined using the tail-flick test. NSCs derived from DRG were able to proliferate to form neurospheres and mainly differentiate into oligodendrocytes in the three-dimensional hydrogel culture system. After transplantation of NSCs encapsulated in hydrogels, NSCs differentiated into oligodendrocytes, neurons or astrocytes in vivo. Moreover, NSCs engrafted on the hydrogels decreased apoptosis and alleviated the ultrastructural and pathological changes of injured cauda equina. Behavioral analysis showed that transplanted hydrogel-encapsulated NSCs decreased the tail-flick latency and showed a neuroprotective role on injured cauda equina. Our results indicate transplantation of hydrogel-encapsulated NSCs promotes stem cell differentiation into oligodendrocytes, neurons or astrocytes and contributes to the functional recovery of injured cauda equina, suggesting that NSCs encapsulated in hydrogels may be applied for the treatment of cauda equina injury.

Modelling bioaccumulation of heavy metals in soil-crop ecosystems and identifying its controlling factors using machine learning.

The prediction and identification of the factors controlling heavy metal transfer in soil-crop ecosystems are of critical importance. In this study, random forest (RF), gradient boosted machine (GBM), and generalised linear (GLM) models were compared after being used to model and identify prior factors that affect the transfer of heavy metals (HMs) in soil-crop systems in the Yangtze River Delta, China, based on 13 covariates with 1822 pairs of soil-crop samples. The mean bioaccumulation factors (BAFs) for all crops followed the order Cd > Zn > As > Cu > Ni > Hg > Cr > Pb. The RF model showed the best prediction ability for the BAFs of HMs in soil-crop ecosystems, followed by GBM and GLM. The R2 values of the RF models for the BAFs of Zn, Cu, Cr, Ni, Hg, Cd, As, and Pb were 0.84, 0.66, 0.59, 0.58, 0.58, 0.51, 0.30, and 0.17, respectively. The primary controlling factor in soil-to-crop transfer of all HMs under study was plant type, followed by soil heavy metal content and soil organic materials. The model used herein could be used to assist the prediction of heavy metal contents in crops based on heavy metal contents in soil and other covariates, and can significantly reduce the cost, labour, and time requirements involved with laboratory analysis. It can also be used to quantify the importance of variables and identify potential control factors in heavy metal bioaccumulation in soil-crop ecosystems.

Estimating spatial and temporal variation in ocean surface pCO2 in the Gulf of Mexico using remote sensing and machine learning techniques.

Research on the carbon cycle of coastal marine systems has been of wide concern recently. Accurate knowledge of the temporal and spatial distributions of sea-surface partial pressure (pCO2) can reflect the seasonal and spatial heterogeneity of CO2 flux and is, therefore, essential for quantifying the ocean's role in carbon cycling. However, it is difficult to use one model to estimate pCO2 and determine its controlling variables for an entire region due to the prominent spatiotemporal heterogeneity of pCO2 in coastal areas. Cubist is a commonly-used model for zoning; thus, it can be applied to the estimation and regional analysis of pCO2 in the Gulf of Mexico (GOM). A cubist model integrated with satellite images was used here to estimate pCO2 in the GOM, a river-dominated coastal area, using satellite products, including chlorophyll-a concentration (Chl-a), sea-surface temperature (SST) and salinity (SSS), and the diffuse attenuation coefficient at 490 nm (Kd-490). The model was based on a semi-mechanistic model and integrated the high-accuracy advantages of machine learning methods. The overall performance showed a root mean square error (RMSE) of 8.42 µatm with a coefficient of determination (R2) of 0.87. Based on the heterogeneity of environmental factors, the GOM area was divided into 6 sub-regions, consisting estuaries, near-shores, and open seas, reflecting a gradient distribution of pCO2. Factor importance and correlation analyses showed that salinity, chlorophyll-a, and temperature are the main controlling environmental variables of pCO2, corresponding to both biological and physical effects. Seasonal changes in the GOM region were also analyzed and explained by changes in the environmental variables. Therefore, considering both high accuracy and interpretability, the cubist-based model was an ideal method for pCO2 estimation and spatiotemporal heterogeneity analysis.

Current status, spatial features, health risks, and potential driving factors of soil heavy metal pollution in China at province level.

In this study we systematically reviewed 1203 research papers published between 2008 and 2018 in China and recorded related data on eight kinds of soil heavy metals (Cr, Pb, Cd, Hg, As, Cu, Zn, and Ni). Based on that, the pollution levels, ecological risk and health risk caused by soil heavy metals were evaluated and the pollution hot spots and potential driving factors of different heavy metals in different provinces were also identified. Results indicated accumulation of heavy metals in soils of most provinces in China compared with background values. Consistent with previous findings, the most prevalent polluted heavy metals were Cd and Hg. Polluted regions are mainly located in central, southern and southwestern China. Hunan, Guangxi, Yunnan, and Guangdong provinces were the most polluted provinces. For the potential health risk caused by heavy metals pollution, children are more likely confront with non-carcinogenic risk than adults and seniors. And children in Hunan and Guangxi province were experiencing relatively larger non-carcinogenic risk. In addition, children in part of provinces were undergoing potentially carcinogenic risks due to soil heavy metals exposure. Furthermore, in our study the 31 provinces in mainland China were divided into six subsets according to corresponding potential driving factors for heavy metal accumulation. Our study provide more comprehensive and updated information for contributing to better soil management, soil remediation, and soil contamination control in China.

Identifying heavy metal pollution hot spots in soil-rice systems: A case study in South of Yangtze River Delta, China.

The soil-rice system in China is subjected to increasing concentrations of heavy metals (HMs) which derived from various sources. It is very critical to investigate the concentrations, spatial characteristics and hot spots of HMs content in the soil-rice system. This study presents work completed on 915 soil-rice sample pairs collected from South of Yangtze River Delta, China. These samples were evaluated for HM concentrations. Ordinary Kriging and the Getis-Ord index were used to explore spatial distributions and pollution hot spots. Averaged HMs content in soil is shown to be Zn > Cr > Pb > Cu > Ni > As > Hg > Cd, and concentrations in rice arrange as Zn > Cu > Cr > Ni > As > Cd > Pb > Hg. Compared with Chinese maximum permissible limits, mean content of all HMs in farmland soil are at safe levels and averaged content of all HMs in rice were also at safe levels except As and Ni. Ni was most polluted HM in soil Most of and showed relatively high content in farmland soil in southeastern part. As and Ni are the most polluted in rice, with highest content distributed in the northwestern and southern area, respectively. The majority of HMs pollution hot spots in soil clustered in the central area. Pollution hot spots of Ni and As in rice are mainly concentrated in the central part and southeastern part, correspondingly. Our results found a weak link between content and spatial pattern of pollution status of HMs in soil and rice. The results are anticipated to contribute to more efficient and accurate control of HMs pollution in soil-rice system, and assist decision-makers achieve a balance between cost and regulation of HM pollution.

Effect of Tubastatin A on the Functional Recovery of Cauda Equina Injury in Rats.

OBJECTIVE: To explore the effect of the inhibitor of histone deacetylase (6HDAC6), tubastatin A, on the functional recovery of injured central branch of dorsal root ganglia (cauda equina). METHODS: A total of 30 Sprague-Dawley rats (n = 10 for each group) were divided randomly into sham operation (sham group), cauda equina compression control (CEC control group), and cauda equina compression plus tubastatin A treatment (tubastatin A group). The tail-flick test was performed to detect the sense of pain and warmth as well as motor function. Immunoblotting/immunofluorescence experiments, terminal deoxynucleotidyl transferase dUTP nick end labeling staining, and hematoxylin-eosin staining were performed to detect the amount of HDAC6 in dorsal root ganglion (DRG) neurons, degree of apoptosis in DRG neurons, and degree of cauda equina injury, respectively. RESULTS: The ratio of apoptotic cells in the CEC control group was greater than that in the sham group, whereas it decreased in the tubastatin A group. Hematoxylin-eosin staining revealed that the fibers of cauda equina in the tubastatin A group were more compact compared with those in the CEC control group. The expression of HDAC6 was not different between the sham and CEC control groups, whereas it decreased significantly in the tubastatin A group. Tubastatin A administration shortened tail-flick latency on the seventh day after operation compared with the CEC control group. CONCLUSIONS: Tubastatin A significantly decreased the expression of HDAC6 in DRG neurons with injured cauda equina, inhibited the apoptosis of neural cells and axonal demyelinating changes in cauda equina, and partially promoted the recovery of neural function.

Source Identification and Apportionment of Trace Elements in Soils in the Yangtze River Delta, China.

Trace elements pollution has attracted a lot of attention worldwide. However, it is difficult to identify and apportion the sources of multiple element pollutants over large areas because of the considerable spatial complexity and variability in the distribution of trace elements in soil. In this study, we collected total of 2051 topsoil (0⁻20 cm) samples, and analyzed the general pollution status of soils from the Yangtze River Delta, Southeast China. We applied principal component analysis (PCA), a finite mixture distribution model (FMDM), and geostatistical tools to identify and quantitatively apportion the sources of seven kinds of trace elements (chromium (Cr), cadmium (Cd), mercury (Hg), copper (Cu), zinc (Zn), nickel (Ni), and arsenic (As)) in soil. The PCA results indicated that the trace elements in soil in the study area were mainly from natural, multi-pollutant and industrial sources. The FMDM also fitted three sub log-normal distributions. The results from the two models were quite similar: Cr, As, and Ni were mainly from natural sources caused by parent material weathering; Cd, Cu, and Zu were mainly from mixed sources, with a considerable portion from anthropogenic activities such as traffic pollutants, domestic garbage, and agricultural inputs, and Hg was mainly from industrial wastes and pollutants.