Association between immunoglobulin A and depression in Chinese older adults: findings from a cross-sectional study.

BACKGROUND: Depression is considered to be an immune-related disease; however, previous studies have focused on inflammatory factors, and there is no conclusive conclusion on the relationships between immunoglobulins and depression. Therefore, the objective of this cross-sectional study was to evaluate the associations between immunoglobulins and depressive symptoms in Chinese older adults. RESULTS: The China Hainan Centenarian Cohort Study (CHCCS) provides a significant population-based sample of older adults in Hainan, China. A total of 1547 older adults were included in this study. A baseline survey was conducted using a structured questionnaire. Blood samples were obtained following standard procedures. The Geriatric Depression Scale (GDS-15) was used to evaluate depressive symptoms of the participants. This sample of older adults had a median age of 94.75 (range: 80-116) years, and the proportion of women was 72.07%. The prevalence of older adults with depressive symptoms was 20.36% (315 older adults). After adjusting for all covariates, we found that immunoglobulin A levels were positively associated with depression. The adjusted reliability of the association between immunoglobulin A and depression was 0.106 (beta) and 1.083 (odds ratio) (P < 0.05 for both). CONCLUSIONS: The present study provides epidemiological evidence that depression has significant associations with immunoglobulin A levels in older adults. Further research should be conducted on the effects of regulating immunoglobulin A to improve depressive symptoms.

Effects of Artificial Islands Construction on the Spatial Distribution and Risk Assessment of Heavy Metals in the Surface Sediments from a Semi-closed Bay (Longkou Bay), China.

Artificial islands construction can significantly influence the spatial distribution of heavy metals in inshore sediments. In this study, the distribution and contamination of heavy metals (Cd, Co, Cr, Cu, Ni, Pb, Zn, As and Hg) in inshore sediments of the Longkou Bay and artificial island adjacent areas were investigated in 2013 and 2014, respectively. Results showed that the contents of heavy metals increased in the Longkou Bay and decreased in the west of the artificial island in 2014 compared with 2013. The contamination and potential eco-risk of heavy metals in the sediments were higher in 2014 than those in 2013. Cd and Hg showed a high potential eco-risk in LK02, and other metals were in the lower level. The results indicated that after the construction of artificial islands in the Longkou Bay, the contamination and eco-risk of heavy metals in the sediments markedly increased in the Longkou Bay.

Effects of continual burial by sediment on seedling emergence and morphology of Suaeda salsa in the coastal marsh of the Yellow River estuary, China.

A greenhouse study was conducted to determine the impacts of continual burial on seedling emergence and morphology of Suaeda salsa, a pioneer species in the coastal marsh of the Yellow River estuary. From May to June 2012, seeds of S. salsa were artificially buried to depths of 0 cm (no burial), 2 cm (burial of 1 mm d(-1)), 4 cm (burial of 2 mm d(-1)), 6 cm (burial of 3 mm d(-1)), 8 cm (burial of 4 mm d(-1)) and 10 cm (burial of 5 mm d(-1)) in plastic pots filled with unsterilized sediment. Results showed that the percent emergence of seedlings had a significantly negative correlation with continual burial depth (p < 0.001). A large percentage of seedlings emerged from 2, 4 and 6 cm burial depths, with the highest emergence (56.00 ± 6.60%) occurring from 2 cm depth. The shortest emergence time occurred at 4 cm burial depth and seeds buried at 10 cm depth took longer to emerge than those at other depths. At shallow or moderate burials, a stimulatory effect on seedling height, stem diameter, number and length of branch, taproot length and dry mass were observed. With increasing burial depth, root-mass and leaf-mass ratios generally increased while stem-mass ratio decreased. Sediment burial also stimulated part of the hypocotyl below the sediment to form adventitious roots, implying that S. salsa seedlings had a special adaptive strategy in response to the rapid and dynamic burial environment in the coastal marsh of the Yellow River estuary. The use of thin-layer continual burial (1-2 mm d(-1)) to promote the emergence of S. salsa seedlings in degraded marsh was feasible, and our study provided another way for the restoration of S. salsa marsh during the initial stage of seedling establishment and laid a good foundation for the scientific decision-making and management of restoration project at a large scale.

Contamination assessment of arsenic and heavy metals in a typical abandoned estuary wetland--a case study of the Yellow River Delta Natural Reserve.

Coastal and estuarine areas are often polluted by heavy metals that result from industrial production and agricultural activities. In this study, we investigated the concentration trait and vertical pattern of trace elements, such as As, Cd, Ni, Zn, Pb, Cu, and Cr, and the relationship between those trace elements and the soil properties in coastal wetlands using 28 profiles that were surveyed across the Diaokouhe Nature Reserve (DKHNR). The goal of this study is to investigate profile distribution characteristics of heavy metals in different wetland types and their variations with the soil depth to assess heavy metal pollution using pollution indices and to identify the pollution sources using multivariate analysis and sediment quality guidelines. Principal component analysis, cluster analysis, and pollution level indices were applied to evaluate the contamination conditions due to wetland degradation. The findings indicated that the concentration of trace elements decreased with the soil depth, while Cd increases with soil depth. The As concentrations in reed swamps and Suaeda heteroptera surface layers were slightly higher than those in other land use types. All six heavy metals, i.e., Ni, Cu, As, Zn, Cr, and Pb, were strongly associated with PC1 (positive loading) and could reflect the contribution of natural geological sources of metals into the coastal sediments. PC2 is highly associated with Cd and could represent anthropogenic sources of metal pollution. Most of the heavy metals exhibited significant positive correlations with total concentrations; however, no significant correlations were observed between them and the soil salt and soil organic carbon. Soil organic carbon exhibited a positive linear relationship with Cu, Pb, and Zn in the first soil layer (0-20 cm); As, Cr, Cu, Ni, Pb, and Zn in the second layer (20-40 cm); and As, Cr, Cu, Ni, Pb, and Zn in the third layer (40-60 cm). Soil organic carbon exhibited only a negative correlation with Cd (P < 0.05), in the second and third layers. As, Cr, Cu, Ni, Pb, and Zn exhibited lower geoaccumulation index values (I geo values), which averaged less than 0 in the three soil layers, this finding indicates that the soils have remained unpolluted by these heavy metals. The mean concentrations of these trace elements were lower than Class I criteria. The degradation wetland restoration suggestions have also been provided in such a way as to restore the reserved flow path of the Yellow River. The results that are associated with trace element contamination would be helpful in providing scientific directions to restore wetlands across the world.

Impacts of spatial expansion by Phragmites australis on spatiotemporal variation of sulfur fractions in marsh soils of the Min River estuary, Southeast China.

To investigate the impacts of spatial expansion by Phragmites australis on spatiotemporal variations of sulfur (S) fractions in marsh soils of the Min River estuary (Southeast China), the contents of total sulfur (TS) and inorganic sulfur (IS) fractions (Water-Soluble-S, W-S-S; Adsorbed-S, A-S; HCl-Soluble-S, H-S-S; and HCl-Volatile-S, H-V-S) were determined in soils of Cyperus malaccensis marsh (before expansion, BE stage), P. australis-C. malaccensis marsh (during expansion, DE stage) and P. australis marsh (after expansion, AE stage) by space-for-time substitution method. Results showed that the expansion of P. australis greatly altered the spatiotemporal variations of TS and IS fractions in marsh soils. The TS contents in soils at AE stage were significantly lower than those at DE and BE stages throughout a year (p < 0.01). Higher levels of W-S-S, A-S, H-S-S and total inorganic sulfur (TIS) generally occurred in soils at DE and AE stages, whereas higher values of H-V-S were observed in soils at BE stage. Although P. australis expansion did not alter the temporal variations of TS stock in soils greatly, the values during autumn and winter were generally higher than those in spring and summer (p < 0.05). The highest TIS stocks in soils of different expansion stages were observed in spring, while the lowest values occurred in summer. The expansion of P. australis significantly increased the IS supply capacity of soils and, compared with the BE stage, stocks of W-S-S, A-S, H-S-S and TIS in soils of all sampling seasons at DE and AE stages increased by 51.40 %, 50.76 %, 63.35 %, 50.52 % and 20.00 %, 31.46 %, 42.93 %, 27.56 %, respectively. It was worth noting that stocks of H-V-S in soils at DE and AE stages showed a decreasing trend compared to the BE stage, implying that the expansion of P. australis might reduce the production of sulfides. This paper found that, compared with C. malaccensis, the increased available IS stocks in soils might be an effective strategy for P. australis to maintain its expansion advantage and the decreased volatile-S in soils might be more favorable for boosting its competitiveness. Our study provided valuable information for understanding the interspecific competition mechanism between P. australis and C. malaccensis. Next step, in order to protect the diversity of marsh vegetations in the Min River estuary, effective measures should be taken to suppress the rapid expansion of P. australis.

Simulated nitrogen load promoted mineralization of N2P1 compounds and accumulation of N4S2 compounds in soil dissolved organic matter in a typical subtropical estuarine marsh.

Soil dissolved organic matter (DOM) is the most reactive pool in estuarine marshes, playing an important role in the biogeochemical processes of biogenetic elements. To investigate the impacts of enhanced nitrogen (N) load on DOM molecular composition and its interactions with microbes in typical Cyperus malaccensis mashes of the Min River estuary, a field N load experiment with four N levels (0, 37.50, 50 and 100 g exogenous N m-2 yr-1, respectively; applied monthly for a total of seven months) was performed. DOM molecular composition was characterized by Fourier transform ion cyclotron resonance mass spectrometry (FT-ICR-MS), the microbial community compositions (MCC, including fungi and bacteria) were determined by high-throughput sequencing technique, and their relationships were presented by co-occurrence network analysis. The results indicated that enhanced N load had significant impacts on soil DOM molecular composition, with N/C and P/C of DOM decreasing but S/C increasing markedly. Meanwhile, enhanced N load decreased the percentages of N2P1 compounds (primarily lipids) but increased those of N4S2 compounds (mainly lignins and lipids). The relative abundances of lignins significantly increased with increasing N load levels, whereas the proportions of lipids decreased. The abundance of N2P1 and N4S2 compounds was primarily positively correlated with eutrophic and oligotrophic microorganisms, respectively. Therefore, mineralization of N2P1 compounds might act as a source to replenish inorganic P, while enrichment of N4S2 compounds may make great contribution to organic S accumulation. Overall, enhanced N load promoted P depletion and S enrichment via altering plant growth, litter decomposition and MCC.

[Effects of shuyu ningxln recipe on the praxiology and the expressions of hippocampal BDNF and trkB of model rats with chronic stress-induced depression].

OBJECTIVE: To observe the effects of Shuyu Ningxin Recipe (SNR) on the praxiology and the expressions of hippocampal brain-derived neurotrophic factor (BDNF) and its receptor tyrosine kinase B (TrkB) of model rats with chronic stress-induced depression, thus exploring its anti-depression mechanisms. METHODS: Sixty adult SD rats were randomly divided into 6 groups, i.e., the normal control group, the model group, the fluoxetine group, the high dose SNR group, the medium dose SNR group, and the low dose SNR group, 10 in each group. All rats were subjected to establish chronic stress-induced depression model for 21 consecutive days. Except those in the normal control group, rats in the rest groups received gastrogavage from the 22nd day. Mice in the model group were administered with normal saline by gastrogavage. SNR at 25.0, 7.5, and 2.5 g/kg was respectively administered to rats in the high dose SNR group, the medium dose SNR group, and the low dose SNR group by gastrogavage. Fluoxetine suspension (12 mg/kg) was given to rats in the fluoxetine group by gastro-gavage. All medication lasted for 3 successive weeks. The weight, open-field test, and the immobility time in forced swimming test were determined before modeling, 3 weeks (after successful modeling), and 6 weeks (by the end of medication). The expressions of hippocampal BDNF and TrkB were measured after the brain tissues were drawn by the end of the experiment. RESULTS: Compared with the normal control group, the body weight grew slowly, the behavior index decreased, the immobility time in forced swimming test was prolonged, and the expressions of BDNF and TrkB were weaken in the model group (P <0.05, P <0.01).The body weight increased, the behavior was improved, the immobility time in forced swimming test was shortened, and the expressions of BDNF and TrkB were enhanced in the high dose SNR group and the fluoxetine group by the and of medication, showing statistical difference when compared with the model group (P <0.05, P <0.01). CONCLUSION: SNR could exert anti-depression by improving the expression levels of hippocampal BDNF and TrkB.

Potential impacts of siltation by Spartina alterniflora on nutrient dynamics in its decomposing litters in coastal marsh of the Min River estuary, southeast China.

The Spartina alterniflora started to invade the Min River estuary (Southeast China) in 2002 and, thereafter, its invasion area showed an increasing trend. Since the siltation depths caused by S. alterniflora in the Min River estuary were much higher (4.8-7.2 cm yr-1) than the values reported in other coastal regions of China (3.5-6.5 cm yr-1), the impacts of siltation on nutrient cycle processes in this region might be more evident. In order to explore the potential effects of siltation by S. alterniflora on nutrient ((carbon (C), nitrogen (N), phosphorous (P) and sulfur (S)) variations in its decaying litters, three one-off siltation treatments (no siltation scenario (0 cm yr-1, NSS), current siltation scenario (5 cm yr-1, CSS) and strong siltation scenario (10 cm yr-1, SSS)) were designed in coastal marsh of the Min River estuary and the in-situ decomposition experiment was conducted from February 2016 to February 2017 by litterbag technique. Results showed that the siltation caused by S. alterniflora showed significant impact on its decomposition rate, following the sequence of NSS (0.005638 d-1) > SSS (0.003005 d-1) > CSS (0.002478 d-1) (p < 0.05). The total carbon (TC) contents in decomposing litters in the three siltation treatments showed dissimilar fluctuations and significantly higher values were observed in the CSS and SSS treatments compared to the NSS treatment. The contents of total nitrogen (TN) and total sulfur (TS) in decomposing detritus in the three siltation treatments generally showed increasing trend during the whole decomposition, while those of total phosphorus (TP) showed increasing trend after decomposing for 30 days. The differences in nutrient variations among the three siltation treatments, to a great extent, rested with the alterations of substrate quality in detritus during the experiment. Although the stocks of C, N, P and S in detritus in the three siltation treatments evidenced the release from litters to the surroundings during decomposition, the release amounts of these nutrients in some periods were at a lower level. With increasing siltation depths, the release of C, N and P from detritus was generally restrained during the whole decomposition, while that of S from decaying litters was inhibited only at the late stage of decomposition. This paper found that the siltation caused by S. alterniflora reduced the nutrient return (particularly for C, N and P) from its detritus, which, in turn, might greatly alter the nutrient cycle in S. alterniflora marsh.

Associations between cardiac structure and function and depressive disorder: A centenarian study in China.

Background: Depressive disorder is a common comorbidity in patients with cardiovascular diseases and is associated with increased hospitalization and death rates. The relationships between cardiac structure and function and depressive disorder remains unclear in the older adults, especially in centenarians. Therefore, this study aimed to explore the possible associations between cardiac structure and function and depressive disorder among centenarians. Methods: In the China Hainan Centenarian Cohort Study, the 15-item Geriatric Depression Scale scores and echocardiography were used to evaluate depressive disorder and cardiac structure and function, respectively. All information, including epidemiological questionnaires, physical examinations, and blood tests, was obtained following standardized procedures. Results: A total of 682 centenarians were enrolled in the study (mean age: 102.35 ± 2.72 years). The prevalence of depressive disorder in centenarians is 26.2% (179 older adults), of whom 81.2% (554 older adults) are women. Centenarians with depressive disorder have significantly higher left ventricular ejection fraction (60.02 ± 3.10) and interventricular septum thickness (9.79 ± 1.54). Stepwise multiple linear regression analysis detected positive associations of left ventricular ejection fraction (Bets: 0.093) and interventricular septum thickness (Bets: 0.440) with Geriatric Depression Scale scores. Both left ventricular ejection fraction (odds ratio: 1.081) and interventricular septum thickness (odds ratio: 1.274) were independently associated with depressive disorder in multiple logistic regression analysis (P < 0.05, all). Conclusions: The prevalence of depressive disorder remains very high, and associations were found between left ventricular ejection fraction, interventricular septum thickness, and depressive disorder in Chinese centenarians. Future studies should focus on their temporal relationships to improve cardiac structure and function, prevent depressive disorder, and achieve healthy aging by coordinating their relationships.

Citrus peel polyphenols alleviate intestinal inflammation in mice with dextran sulfate sodium-induced acute colitis.

Citrus peel polyphenols have possess the distinct anti-inflammatory activities. However, its underlying mechanism on ulcerative colitis have not been elucidated. The aim of this research was to investigate the anti-inflammatory effect and action mechanisms of citrus peel polyphenols. Total citrus peel polyphenols were concentrated using macroporous resins and separated into water-soluble citrus polyphenols and ester-soluble citrus peel polyphenols. These extracts were then gavaged to acute colitis mice induced by dextran sulfate sodium for 14 days using a dose of 300 mg/kg▪bw. High performance liquid chromatography results showed that the extracts contained flavanones, flavonoids, and phenolic acids. Compared to the dextran sulfate sodium group, total citrus peel polyphenols, water-soluble citrus polyphenols, and ester-soluble citrus peel polyphenols significantly ameliorated the severity of colitis symptoms. Additionally, citrus peel polyphenols reduced the activity of myeloperoxidase, lowered secretion of tumor necrosis factor-α and interleukin-6, and increased interleukin-10. Meanwhile, total citrus peel polyphenols, water-soluble citrus polyphenols, and ester-soluble citrus peel polyphenols effectively blocked the activation of the nuclear factor-kappa B. These results demonstrated that citrus peel polyphenols alleviated ulcerative colitis in mice by damping pro-inflammatory cytokine secretion and suppressing the nuclear factor-kappa B pathway activation.

Positive associations between menstrual lifespan, geriatric depression and healthy longevity in Chinese oldest-old and centenarian women.

OBJECTIVE: Menstrual lifespan (ML) is an important biological characteristic for women. Rare evidence has established the associations between menopause age (MI), geriatric depression and healthy longevity. This study aimed to address these associations in Chinese oldest-old and centenarian women, and explore their related factors in order to provide strategy support for healthy aging. METHODS: The China Hainan Centenarian Cohort Study provides a population-based sample in Hainan, China. A total of 723 women including 318 centenarian women and 405 oldest-old women aged 80-99 years were included in this study. Data on demographic information were collected using a structured questionnaire. Physical examination and blood samples were obtained following standard procedure. Geriatric Depression Scale (GDS-15) was used to evaluate depressive symptoms for all participants. RESULTS: The proportions of participants with depression and longevity were 19.78 % (143 older adults) and 43.98 % (318 older adults), respectively. After adjusting for a wide range of other covariates in multiple logistic regression analyses, ML was positively and significantly associated with depression and longevity [Exp(ß) 1.076 and 1.121; P < 0.05 for all]. In multiple linear regression analyses, there were significantly positive associations of ML with GDS-15 (ß = 0.061) and age (ß = 0.238, p < 0.05 for all) after adjusting for all covariates. CONCLUSIONS: This study provides epidemiological evidence that menstrual lifespan has positive associations with geriatric depression and healthy longevity in Chinese oldest-old and centenarian women. Future researches should focus on the effects of intervening MI on psychological health and successful longevity.

Antidepressant-like effects of shuyusan in rats exposed to chronic stress: effects on hypothalamic-pituitary-adrenal function.

This study was to investigate antidepressant activities of Shuyusan (a Chinese herb), using a rats model of depression induced by unpredictable chronic mild stress (UCMS). The administration groups were treated with Shuyusan decoction for 3 weeks and compared with fluoxetine treatment. In order to understand the potential antidepressant-like activities of Shuyusan, tail suspension test (TST) and forced swimming test (FST) were used as behavioral despair study. The level of corticotropin-releasing factor (CRH), adrenocorticotropic hormone (ACTH), corticosterone (CORT) and hippocampus glucocorticoid receptor expression were examined. After modeling, there was a significant prolongation of immobility time in administration groups with the TST and FST. High-dose Shuyusan could reduce the immobility time measured with the TST and FST. The immobility time in high-dose herbs group and fluoxetine group was increased significantly compared with the model group. After 3 weeks herbs fed, the serum contents level of CRH, ACTH, and CORT in high-dose herb group was significantly decreased compared to the model group. The result indicated that Shuyusan had antidepressant activity effects on UCMS model rats. The potential antidepressant effect may be related to decreasing glucocorticoid levels activity, regulating the function of HPA axis, and inhibiting glucocorticoid receptor expression in hippocampus.

Spatial variation and ecological risk assessment for heavy metals in marsh sediments in Fuzhou reach of the Min River, Southeast China.

To explore the pollution levels, sources and risks of heavy metals in sediments in Fuzhou reach of the Min River, the sediments involving in seven marsh types were sampled. Results showed that the concentrations of Pb, Zn and Cd in sediments declined from freshwater segment to estuarine segment. Higher levels of Cu, Cr and Ni in sediments generally occurred in estuarine segment. The highest levels of Pb and Cd were observed in bush swamp, while those of Cr, Ni, Zn and Cu occurred in mudflat. Cr, Cu, Zn and Ni probably shared common source, while Pb and Cd originated from another source. Pb and Cd were identified as heavy metals of primary concerns and the former showed high potential toxicity and high contributions to ΣTUs. Next step, the metal pollutions in sediments might be more serious if effective measures were not taken to control the loading of pollutants.

[Sulfur oxidation-reduction process and its coupling effects with other elements in marsh soil: A review]. / 湿地土壤硫氧化-è¿˜åŽŸè¿‡ç¨‹åŠå ¶ä¸Žå ¶ä»–å ƒç´ çš„è€¦åˆä½œç”¨ç ”ç©¶è¿›å±•.

Sulfur oxidation-reduction process (SORP) in marsh soil is an important link in sulfur cycle, which plays an important role in maintaining the stability and health of marsh. We summarized the SORP in marsh soil and its influencing factors, and analyzed the research progress of its coupling effects with other elements. The influencing factors of SORP in marsh soil mainly involved biotic (plants, microorganisms, zoobenthos, human activities, etc.) and abiotic factors (physical factors such as temperature, moisture and particle size, and chemical factors such as pH, salinity, organic matter, etc.). Related research on the coupling effects of SORP and other elements in marsh soil mainly involved in biogenic elements such as carbon (C), nitrogen (N) and phosphorus (P), and metal elements such as iron (Fe) and manganese (Mn). Currently, the underlying mechanism of SORP was not deeply explored, the research on coupling effects was unbalance, and the ecological effects were insufficient. In the future, key functional microorganisms involved in SORP should be strengthened, the coupling mechanism between SORP and micro-elements should be enhanced, and the ecological effects produced by the coupling effects of SORP with other elements should be emphasized.

Associations between constipation, overeating, and depression: A survey of Chinese oldest-old and centenarians.

Objectives: Depression is a common disease of elderly population, with a global prevalence of more than 20%. Few studies have involved the associations of constipation and overeating with depression, especially in the elderly population. We aimed to address these associations in Chinese oldest-old and centenarians. Methods: A total of 1863 elderly individuals from 18 regions of Hainan, China, were investigated from July 2014 to December 2016. Health survey, physical examination, and blood analyses were performed through structured questionnaires and standard procedures. The Geriatric Depression Scale (GDS-15) was used to measure depression. Results: The proportions of elderly individuals with depression, constipation, and overeating were 20.80% (349), 15.14% (254), and 26.52% (445), respectively. The prevalence of constipation and overeating was significantly higher in the elderly group with depression than in those without depression (P < 0.05, all). In the multiple linear regression analyses, higher prevalence of constipation and overeating had positive and significant associations with the GDS-15 (P < 0.05, all). In the multiple logistic regression analyses, constipation (odds ratio [OR]: 2.328; 95% confidence interval [CI]: 1.540-3.521) and overeating (OR: 2.735; 95% CI: 1.920-3.898) had positive and significant associations with depression (P < 0.05, in all). Conclusions and Implications: This study provides epidemiological evidence that constipation and overeating have positive associations with depression in Chinese oldest-old and centenarians. The interventions for constipation and overeating should be improved to promote prevention and treatment for depression and achieve successful aging and healthy longevity.

[Phosphorus forms in marsh soils with different years of Spartina alterniflora invasion in the Minjiang River estuary, China]. / é—½æ±Ÿæ²³å£äº’èŠ±ç±³è‰ä¸åŒå ¥ä¾µå¹´é™æ¹¿åœ°åœŸå£¤ç£·èµ‹å­˜å½¢æ€.

We examined the effects of Spartina alterniflora invasion on phosphorus forms of marsh soils, based on the method of space-for-time substitution by selecting S. alterniflora marshes with different invasion years (SA1, 5-6 years; SA2, 8-10 years; and SA3, 12-14 years) in Shanyutan of the Minjiang River estuary. The results showed that in marsh soils of different invasion years, the proportion of hardly decomposable phosphorus (HCl-Pi and Residual-P) was the highest (46.4%-46.7%), followed by moderately decomposable phosphorus (NaOH-Pi, NaOH-Po and Sonic-Pi) (40.0%-44.0%), and the easily decomposable phosphorus (Resin-Pi, NaHCO3-Pi and NaHCO3-Po) was the lowest (9.5%-13.3%). With increasing invasion years of S. alterniflora, soil phosphorus forms and their spatial distributions were greatly altered. The contents of moderately decomposable phosphorus, hardly decomposable phosphorus, and total phosphorus (TP) generally increased, while easily decomposable phosphorus content generally decreased. Compared with SA1, the contents of moderately decomposable phosphorus, hardly decomposable phosphorus and TP in SA2 increased by 11.5%, 9.7% and 10.5%, while those in SA3 increased by 24.8%, 13.2% and 13.5%, respectively. The distribution of phosphorus forms was greatly altered with increasing invasion years, which was dependent on the variations of key factors such as EC, pH value and grain composition. The implementation of regular mowing activities for S. alterniflora in the Minjiang River estuary in recent years, to some extent, reduced the return of phosphorus from residues to soils and decreased the availability of the easily decomposable phosphorus in soils.

Relationships Between Traditional Chinese Medicine Constitution and Age-Related Cognitive Decline in Chinese Centenarians.

Background: Age-related cognitive decline (ARCD) is a common condition among older adults, affecting 100 million people worldwide. Traditional Chinese Medicine's (TCM) constitution is closely related to the occurrence and development of diseases in the elderly population. However, little is known about the relationships between TCM constitution and ARCD in the super-aged population. The present study aimed to investigate the relationships between the TCM constitution and ARCD in Chinese centenarians and to explore the application of the constitution to prevent ARCD in the elderly population. Methods: Each participant underwent a standardized epidemiological investigation and physical examination, based on the China Hainan Centenarian Cohort Study. Data on the demographic characteristics and TCM constitution were collected using structured questionnaires. Results: The present study included 636 centenarians aged 100-116 years. The prevalence of ARCD was 87.7% (n = 558 centenarians). In multiple linear regression analysis, an inverse relationship between Qi depression and Mini-Mental State Examination scales was significant after controlling for a wide range of other factors (P < 0.05). In multiple logistic regression analysis, Qi depression was positively associated with ARCD after full adjustment (P < 0.05). Conclusion: As the first study in the world, the present study provides strong epidemiological evidence that Qi depression has a significant relationship with ARCD in Chinese centenarians, and regulating Qi depression may be a valuable method to prevent and treat ARCD in the elderly population.

[Structure and diversity of nirK-type denitrifying microbial community in marsh soils at different invasion stages of Spartina alterniflora in the Minjiang River estuary, China.] / é—½æ±Ÿæ²³å£äº’èŠ±ç±³è‰ä¸åŒå ¥ä¾µé˜¶æ®µæ¹¿åœ°åœŸå£¤nirKåž‹åç¡åŒ–å¾®ç”Ÿç‰©ç¾¤è½ç»“æž„åŠå¤šæ ·æ€§.

To explore the differences in structure and diversity of nirK-type denitrifying microbial community in marsh soils at different invasion stages of Spartina alterniflora, the mudflat (MF, before invasion) and the S. alterniflora marsh after seaward invasion for 1-2 years (SAN) and 6-7 years (SA) in Shanyutan of the Minjiang River estuary were investigated by high-through put sequencing method. Results showed that the seaward invasion of S. alterniflora reduced the richness and diversity of nirK-type denitrifying microbial community in marsh soils. The nirK-type denitrifying microbial community in soils at different invasion stages included Proteobacteria and Actinobacteria, with Proteobacteria as the dominant one. The seaward invasion of S. alterniflora greatly altered the composition of nirK-type denitrifying microbial community in marsh soils. The highest relative abundance of genus in soils from different invasion stages were Bradyrhizobium, Mesorhizobium and Alcaligenes, respectively. The seaward invasion of S. alterniflora increased the spatial heterogeneity of nirK-type denitrifying microbial community composition in marsh soils. In SAN plot, the enhancement of spatial heterogeneity was primarily due to higher environmental disturbances in plots and the increased spatial heterogeneity of environmental variables caused by the seaward invasion of S. alterniflora. The seaward invasion of S. alterniflora altered the physico-chemical properties (e.g., grain composition, pH and moisture) and N nutrient conditions (total N, NH4+-N and NO3--N) in marsh soils, which greatly altered the structure and diversity of nirK-type denitrifying microbial community. Our findings reveal the microbial mechanism of denitrification process in marsh soils during the seaward invasion of S. alterniflora.

Nitrogen cycle of a typical Suaeda salsa marsh ecosystem in the Yellow River estuary.

The nitrogen (N) biological cycle of the Suaeda salsa marsh ecosystem in the Yellow River estuary was studied during 2008 to 2009. Results showed that soil N had significant seasonal fluctuations and vertical distribution. The N/P ratio (15.73 +/- 1.77) of S. salsa was less than 16, indicating that plant growth was limited by both N and P. The N absorption coefficient of S. salsa was very low (0.007), while the N utilization and cycle coefficients were high (0.824 and 0.331, respectively). The N turnover among compartments of S. salsa marsh showed that N uptake from aboveground parts and roots were 2.539 and 0.622 g/m2, respectively. The N translocation from aboveground parts to roots and from roots to soil were 2.042 and 0.076 g/m2, respectively. The N translocation from aboveground living bodies to litter was 0.497 g/m2, the annual N return from litter to soil was far less than 0.368 g/m2, and the net N mineralization in topsoil during the growing season was 0.033 g/m2. N was an important limiting factor in S. salsa marsh, and the ecosystem was classified as unstable and vulnerable. S. salsa was seemingly well adapted to the low-nutrient status and vulnerable habitat, and the nutrient enrichment due to N import from the Yellow River estuary would be a potential threat to the S. salsa marsh. Excessive nutrient loading might favor invasive species and induce severe long-term degradation of the ecosystem if human intervention measures were not taken. The N quantitative relationships determined in our study might provide a scientific basis for the establishment of effective measures.

Effects of exogenous nitrogen import on variations of nutrient in decomposing litters of Suaeda salsa in coastal marsh of the Yellow River estuary, China.

To explore the effects of exogenous nitrogen (N) import on decomposition of Suaeda salsa in coastal marsh of the Yellow River estuary, the decomposition rates and the variations of nutrient (C, N, P, and S) in decomposing litters were investigated from May 2014 to November 2015. The in situ experiment included four N addition treatments: N0 (no N import treatment, 0 g N·m-2·year-1), Nlow (low N import treatment, 3.0 g N·m-2·year-1), Nmedium (medium N import treatment, 6.0 g N·m-2·year-1), and Nhigh (high N import treatment, 12.0 g N·m-2·year-1). Results showed that N enrichment showed significant influence on the decomposition rate of S. salsa, in the order of Nmedium (0.00112 d-1) > Nhigh (0.00096 d-1) > Nlow(0.00092 d-1) > N0 (0.00075 d-1) (p < 0.05). Compared to the N0 treatment, the decomposition rates of S. salsa in the Nlow, Nmedium, and Nhigh treatments increased by 22.76%, 49.33%, and 28.00%, respectively. The contents of TC in decomposing litters in the four N import treatments generally showed a decreasing trend, while those of TN and TP showed an increasing trend. By comparison, dissimilar variations of TS contents in decomposing litters were observed among the four treatments. The differences in decomposition rate and nutrient variation among the four N addition treatments might be dependent on the alterations of substrate quality in decomposing litters. With a few exceptions, stocks of C and S in decomposing litters generally evidenced the export from litters to the environment, while those of N and P showed net accumulation. As N addition reached Nmedium level, although the C released from decomposing litters to the surroundings was stimulated, the S return was restrained. Moreover, N additions generally promoted the accumulation of N and P in decomposing litters. This paper found that, with increasing N addition, the decomposition rates and the nutrient variations in S. salsa would be altered greatly and the alteration was particularly evident in the Nmedium treatment. From the perspective of nutrient return, as N enrichment reached or exceeded Nmedium level in future, the deficient status of P and S in S. salsa marsh might be serious, which would affect the stability and health of ecosystems.