首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 31 毫秒
1.
Crop residues like corn (Zea mays L.) stover perform important functions that promote soil health and provide ecosystem services that influence agricultural sustainability and global biogeochemical cycles. We evaluated the effect of corn stover removal from a no-till, corn-soybean (Glycine max (L.) Merr) rotation on soil greenhouse gas (GHG; CO2, N2O, CH4) fluxes, crop yields, and soil organic carbon (SOC) dynamics. We conducted a 4-year study using replicated field plots managed with two levels of corn stover removal (none; 55 % stover removal) for four complete crop cycles prior to initiation of ground surface gas flux measurements. Corn and soybean yields were not affected by stover removal with yields averaging 7.28 Mg ha?1 for corn and 2.64 Mg ha?1 for soybean. Corn stover removal treatment did not affect soil GHG fluxes from the corn phase; however, the treatment did significantly increase (107 %, P?=?0.037) N2O fluxes during the soybean phase. The plots were a net source of CH4 (~0.5 kg CH4-C ha?1 year?1 average of all treatments and crops) during the generally wet study duration. Soil organic carbon stocks increased in both treatments during the 4-year study (initiated following 8 years of stover removal), with significantly higher SOC accumulation in the control plots compared to plots with corn stover removal (0–15 cm, P?=?0.048). Non-CO2 greenhouse gas emissions (945 kg CO2-eq ha?1 year?1) were roughly half of SOC (0–30 cm) gains with corn stover removal (1.841 Mg CO2-eq ha?1 year?1) indicating that no-till practices greatly improve the viability of biennial corn stover harvesting under local soil-climatic conditions. Our results also show that repeated corn stover harvesting may increase N loss (as N2O) from fields and thereby contribute to GHG production and loss of potential plant nutrients.  相似文献   

2.
Corn (Zea mays L.) residue removal at high rates can result in negative impacts to soil ecosystem services. The use of cover crops could be a potential strategy to ameliorate any adverse effects of residue removal while allowing greater removal levels. Hence, the objective of this study was to determine changes in water erosion potential, soil organic C (SOC) and total N concentration, and crop yields under early- and late-terminated cover crop (CC) combined with five levels of corn residue removal after 3 years on rainfed and irrigated no-till continuous corn in Nebraska. Treatments were no CC, early- and late-terminated winter rye (Secale cereale L.) CC, and 0, 25, 50, 75, and 100% corn residue removal rates. Complete residue removal reduced mean weight diameter (MWD) of water-stable aggregates (5 cm depth) by 29% compared to no removal at the rainfed site only, suggesting increased water erosion risk at rainfed sites. Late-terminated CC significantly increased MWD of water-stable aggregates by 27 to 37% at both sites compared to no CC, but early-terminated CC had no effect. The increased MWD with late-terminated CC suggests that CC when terminated late can offset residue removal-induced risks of water erosion. Residue removal and CC did not affect SOC and total soil N concentration. Particulate organic matter increased with late-terminated CC at the irrigated site compared to no CC. Complete residue removal increased irrigated grain yield by 9% in 1 year relative to no removal. Late-terminated CC had no effect on corn yield except in 1 year when yield was 8% lower relative to no CC due to low precipitation at corn establishment. Overall, late-terminated CC ameliorates residue removal-induced increases in water erosion potential and could allow greater levels of removal without reducing corn yields in most years, in the short term, under the conditions of this study.  相似文献   

3.
A clear understanding of how crop root proliferation affects the distribution of the spore abundance of arbuscular mycorrhizal fungi (AMF) and the composition of AMF communities in agricultural fields is imperative to identify the potential roles of AMF in winter cover crop rotational systems. Toward this goal, we conducted a field trial using wheat (Triticum aestivum L.) or red clover (Trifolium pratense L.) grown during the winter season. We conducted a molecular analysis to compare the diversity and distribution of AMF communities in roots and spore abundance in soil cropped with wheat and red clover. The AMF spore abundance, AMF root colonization, and abundance of root length were investigated at three different distances from winter crops (0 cm, 7.5 cm, and 15 cm), and differences in these variables were found between the two crops. The distribution of specific AMF communities and variables responded to the two winter cover crops. The majority of Glomerales phylotypes were common to the roots of both winter cover crops, but Gigaspora phylotypes in Gigasporales were found only in red clover roots. These results also demonstrated that the diversity of the AMF colonizing the roots did not significantly change with the three distances from the crop within each rotation but was strongly influenced by the host crop identity. The distribution of specific AMF phylotypes responded to the presence of wheat and red clover roots, indicating that the host crop identity was much more important than the proliferation of crop roots in determining the diversity of the AMF communities.  相似文献   

4.
The association between alcoholic liver disease (ALD) and the inflammatory response remains controversial. The aim of this study was to explore this association between ALD and inflammation. We enrolled 214 male participants, who were divided into three age-matched groups: ALD (n?=?135), chronic alcohol ingestion without ALD (non-ALD; n?=?42), and control (n?=?37). The BMI was significantly higher in the ALD group than in the non-ALD and control groups (all P?=?0.000). Further, the constituent ratio of the liver inflammatory level was significantly higher in the ALD group than in the non-ALD and control groups (P?=?0.002 and P?=?0.000, respectively). In addition, the median serum ALT, AST, and GGT levels were significantly higher in the ALD group than in the control group (P?=?0.023, P?=?0.008, and P?=?0.000, respectively); these levels were also significantly higher in the ALD group than in the non-ALD group (P?=?0.013, P?=?0.010, and P?=?0.000, respectively). The median serum CRP level was significantly higher in the ALD group than in the non-ALD and control groups (P?=?0.006 and P?=?0.000, respectively). Further, the median serum TNF-α level was significantly lower in the ALD group than in the non-ALD and control groups (P?=?0.004 and P?=?0.000, respectively). The median serum sOX40L and HSP70 levels were significantly lower in the ALD group than in the control group (P?=?0.008 and P?=?0.018, respectively). In addition, the ALT, AST, and GGT levels were positively correlated with the CRP level (r?=?0.211, P?=?0.002; r?=?0.220, P?=?0.001 and r?=?0.295, P?=?0.000, respectively), and the GGT level was negatively correlated with the TNF-α (r?=??0.225, P?=?0.001), sOX40L (r?=??0.165, P?=?0.016), and HSP70 levels (r?=??0.178, P?=?0.009). Further, the Cr level was negatively correlated with the IL-10 level (r?=??0.166, P?=?0.015). Logistic regression analysis verified that the BMI (OR??=??1.637, 95%CI: 1.374–1.951, P??=??0.000) and GGT level were significantly higher (OR??=??1.039, 95%CI: 1.020–1.059, P??=??0.000) and that the TNF-α (OR??=??0.998, 95%CI: 0.996–1.000, P??=??0.030) and HSP70 levels were significantly lower (OR??=??1.017, 95%CI: 1.003–1.031, P??=??0.029) in the ALD group than in the non-ALD group. Further, the moderate-to-severe ALD patients had a significantly higher serum CRP level (Or?=???1.349, 95%CI: 1.066–1.702, P??=??0.013) and significantly lower HSP60 (OR??=??0.965, 95%CI: 0.938–0.993, P??=??0.014) and HSP70 levels (OR??=??0.978, 95%CI: 0.962–0.995, P??=??0.010) than the mild ALD patients. These results suggest that ALD patients may present with obesity, liver damage, and an imbalanced inflammatory immune response, mainly manifesting as decreased levels of immune inflammatory cytokines. In addition, they suggest that certain liver and kidney function parameters and ALD severity are either positively or negatively correlated with certain inflammatory cytokines. Hence, ALD patients may be at increased risks of obesity- and inflammation-related diseases. Accordingly, to control the inflammatory response, preventative measures for patients with this disease should include weight control and protection of liver and kidney function.  相似文献   

5.
Epithelial stromal interaction 1 (EPSTI1) is an interferon (IFN) response gene, which was originally identified as a stromal fibroblast-induced gene in breast cancer. Our previous study using a customized SNP chip found evidence of an association between EPSTI1 and susceptibility to the chronic inflammatory disease, systematic lupus erythematosus (SLE). This study aimed to validate whether polymorphisms in EPSTI1 are associated with susceptibility to SLE. We analyzed genotype and allele frequencies of SNPs at EPSTI1 using genomic DNA from 119 patients with SLE and 512 healthy controls. We found that the genotype frequencies of rs1044856 and rs1359184 in patients with SLE were significantly different from those found in the control group (P?=?0.03 and P?=?0.01, respectively). In addition, we found that genotype and allele frequencies of rs1359184 in female patients with SLE were significantly different from those found in female controls (P?=?0.02 and P?=?0.04, respectively). We identified two major haplotypes in EPSTI1 that were significantly different between patients with SLE and healthy controls (P?=?0.01 and P?=?0.05, respectively). Furthermore, we found that rs1359184 and rs1044856 in EPSTI1 were associated with antinuclear antibody (ANA) and erythrocyte sedimentation rate (ESR) levels in patients with SLE (P?=?0.0035 and P?=?0.021, respectively). Our findings indicate that polymorphisms in EPSTI1 are associated with susceptibility to SLE and that haplotypes at EPSTI1 may be useful genetic markers for SLE.  相似文献   

6.

Background and aims

Variations in root-associated fungal communities contribute to the so-called ‘crop rotation benefit’ on soil productivity. We assessed the effects of chickpea, lentil, and pea in wheat-based rotations, as compared to wheat monoculture, on the structure of root-associated fungal communities, and described the legacy of pulses on a following wheat crop.

Methods

The internal transcribed spacer (ITS) and 18S rRNA gene markers, and 454 amplicon pyrosequencing were used to describe the fungal communities of crop roots and rhizosphere soil in a field experiment and agronomic data were collected.

Results

Pulses influenced only the structure of the non-mycorrhizal fungal community of roots. Fusarium tricinctum, Clonostachys rosea, Fusarium redolens, and Cryptococcus sp. were specific to certain crops. Despite the absence of selective effects of pulses on their associated arbuscular mycorrhizal (AM) fungal community, pea had a legacy effect on the structure of the AM fungal community associated with the roots of the following wheat crop, in one of the two year/sites examined. Species of Mortierella, Cryptococcus, and Paraglomus in wheat rhizosphere soil may benefit yield, whereas species of Fusarium, Davidiella, Lachnum, Sistotrema and Podospora may reduce yield.

Conclusion

The effect of pulse crops on root fungal communities varied with rotation crop species. Pulses had various effects on the physiology of the following wheat crop, including increased productivity.
  相似文献   

7.
The purpose of this study was to investigate the short-term effects of maize (Zea mays)-fallow rotation, residue management, and soil water on carbon mineralization in a tropical cropping system in Ghana. After 15 months of the trial, maize–legume rotation treatments had significantly (P?C 0 (μg CO2–C g?1) than maize–elephant grass (Pennisetum purpureum) rotations. The C 0 for maize–grass rotation treatments was significantly related to the biomass input (r?=?0.95; P?=?0.05), but that for the maize–legume rotation was not. The soil carbon mineralization rate constant, k (per day), was also significantly related to the rotation treatments (P?k values for maize–grass and maize–legume rotation treatments were 0.025 and 0.036 day?1 respectively. The initial carbon mineralization rate, m 0 (μg CO2–C g?1 day ?1), was significantly (P?θ. The m 0 ranged from 3.88 to 18.67 and from 2.30 to 15.35 μg CO2–C g?1 day?1 for maize–legume and maize–grass rotation treatments, respectively, when the soil water varied from 28% to 95% field capacity (FC). A simple soil water content (θ)-based factor, f w, formulated as: \(f_{\text{w}} = \left[ {\frac{{\theta - \theta _{\text{d}} }}{{\theta _{{\text{FC}}} - \theta _{\text{d}} }}} \right]\), where θ d and θ FC were the air-dry and field capacity soil water content, respectively, adequately described the variation of the m 0 with respect to soil water (R 2?=?0.91; RMSE?=?1.6). Such a simple relationship could be useful for SOC modeling under variable soil water conditions.  相似文献   

8.
Large-scale marshland reclamation can cause substantial changes to the soil fungal community by disturbances associated with the growth of crop plants and by the addition of fertilizers and pesticides. In this study, high-throughput sequencing of the fungal-specific internal transcribed spacer (ITS) gene region was used to identify fungal taxa. We analyzed the variation in soil fungi diversity and community composition in marshland, paddy, and farmland corn soils, and investigated the relationship between soil fungal community composition and soil physicochemical characteristics to quantify the effect of large-scale reclamation on marshland soil environment in the Sanjiang Plain, northeast China. Marshland soil contained most of the 1997 operational taxonomic units (OTUs) found across all sites (1241), while paddy soil had only 614 OTUs and farmland corn soil 817 OTUs. All reclaimed lands presented a decline in richness and diversity of soil fungi at the OTU level, and soil fungal richness was significantly different between marshland and reclaimed sites (P < 0.05), although it did not differ significantly between marshland and farmland corn sites. Additionally, soil fungal community composition showed different trends and structure after the reclamation. One-way analysis of variance showed Basidiomycota, Zygomycota, Glomeromycota, and Chytridiomycota composition differed significantly between marshland and reclaimed sites (P < 0.05). Nine dominant genera (relative abundance >1.5% in at least one site) and many unclassified genera showed significant variation between marshland and reclaimed sites, including Blumeria, Tomentella, Peziza, Hypholoma, Zopfiella, Mrakia, and Fusarium. Soil fungal community composition and diversity were affected by soil moisture, pH, total carbon (C), available nitrogen (N), soil organic carbon, soil dissolved organic carbon, and C/N (the ratio of total carbon to total nitrogen). The present results contribute to understanding the fungal community in marshland ecosystems, and the role of environmental variability as a predictor of fungal community composition.  相似文献   

9.
Although the current glucocorticoids (GCs) treatment for systemic lupus erythematosus (SLE) is effective to a certain extent, the difference in therapeutic effect between patients is still a widespread problem. Some patients can have repeated attacks that greatly diminish their quality of life. This study was conducted to investigate the relationship between HSP90AA2 polymorphisms and disease susceptibility, GCs efficacy and health-related quality of life (HRQoL) in Chinese SLE patients. A case–control study was performed in 470 SLE patients and 470 normal controls. Then, 444 patients in the case group were followed up for 12 weeks to observe efficacy of GCs and improvement of HRQoL. Two single nucleotide polymorphisms (SNPs) of HSP90AA2 were selected for genotyping: rs1826330 and rs6484340. HRQoL was assessed using the SF-36 questionnaire. The minor T allele of rs1826330 and the TT haplotype formed by rs1826330 and rs6484340 showed associations with decreased SLE risk (T allele: PBH?=?0.022; TT haplotype: PBH?=?0.033). A significant association between rs6484340 and improvement of HRQoL was revealed in the follow-up study. Five subscales of SF-36 were appeared to be influenced by rs6484340: total score of SF-36 (additive model: PBH?=?0.026), physical function (additive model: PBH?=?0.026), role-physical (recessive model: PBH?=?0.041), mental health (dominant model: PBH?=?0.047), and physical component summary (additive model: PBH?=?0.026). No statistical significance was found between HSP90AA2 gene polymorphisms and GCs efficacy. These results revealed a genetic association between HSP90AA2 and SLE. Remarkably, HSP90AA2 has an impact on the improvement of HRQoL in Chinese population with SLE.  相似文献   

10.

Background

The value of apparent diffusion coefficient (ADC) values and quantitative parameters (Ktrans, Kep, Ve) in detecting prognostic factor at 3.0 Tesla remains unclear, especially in predicting prognosis of breast cancer.

Methods

A total of 151 patients with IDC underwent breast DCE-MRI and DWI-MRI at 3.0 Tesla following surgery. The ADC values were acquired with b values of 0 and 1000?s/mm2. The relationship between ADC values or DCE-MRI quantitative parameters and size, histologic grade (HG), lymph node metastasis (LNM), ER, PR, and Ki67 was evaluated. The predictive values of ADC, Ktrans, Kep, and Ve to prognosis of IDC were assessed.

Results

ADC value was positively related to size (P?=?0.04) and HER2 (P?=?0.046) expression and negatively related to ER (P?=?0.012) and PR (P?<?0.001) expression. Ktrans value has positive correlation with size (P?<?0.001), HG (P?<?0.001), LNM (P?<?0.001), HER2 (P?=?0.007), and Ki67 (P?<?0.001) expression and negative correlation with ER (P?<?0.001) and PR (P?<?0.001) expression. Kep value was positively related to size (P?<?0.001) and negatively related to ER (P?<?0.001) and PR (P?<?0.001) expression. Ve value was negatively related to HER2 expression (P?=?0.004). The Cox hazard ratio (HR) of ADC, Ktrans, Kep, and Ve values on survival was 5.26 (P?=?0.093), 1.081 (P?=?0.002), 1.006 (P?=?0.941), and 0.883 (P?=?0.926), respectively.

Conclusions

Ktrans value was a best predictive indicator of HG, LNM, ER, PR, and Ki67 expression, and ADC value was the best predictive indicator of HER2. Preoperative use of the 3.0 Tesla could provide important information to determine the optimal treatment plan.
  相似文献   

11.
Soil organic carbon (SOC) is an important soil property and is strongly influenced by management. Changes in SOC stocks are difficult to measure through direct sampling, requiring both long time periods and intensive sampling to detect small changes in the large, highly variable pool. Models have the potential to predict management-induced changes in SOC stocks, but require long-term data sets for validation. CQESTR is a processed-based C model that uses site weather, management, and crop data to estimate changes in SOC stocks. Crop residue removal for livestock feed or future biofuel feedstock use is a management practice that potentially affects SOC stocks. Simulated changes in SOC using CQESTR were compared to measured SOC changes over 10 years for two contrasting residue removal studies in eastern Nebraska. The rainfed study compared SOC changes in no-tillage continuous corn grown under two N fertilizer rates (120 or 180 kg N ha?1) and two residue removal rates (0 or 50 %). The irrigated study compared SOC changes in continuous corn grown under no-tillage or disk tillage and three residue removal rates (0, 35, or 70 %). After 10 years under these management scenarios, CQESTR-estimated SOC stocks agreed well with the measured SOC stocks at both sites (r 2?=?0.93 at the rainfed site and r 2?=?0.82 at the irrigated site). These results are consistent with other CQESTR validation studies and demonstrate that this process-based model can be a suitable tool for supporting current management and long-term planning decisions.  相似文献   

12.

Background and Objectives

This study aimed to assess the changes of RA function in patients with obstructive sleep apnea syndrome (OSAS) using velocity vector imaging (VVI) and to evaluate the application of VVI technology.

Methods

According to the apnea–hypopnea index (AHI), 71 patients with OSAS were divided into three groups: mild, moderate, and severe. A total of 30 cases of healthy subjects were enrolled as the control group. Digital images of apex four-chamber views were acquired to measure the right atrium (RA) linear dimensions and volume parameters including RA longitudinal diameter (RAL), transverse diameter (RAT), RA maximum volume (Vmax), RA minimum volume (Vmin), right atrial volume before contraction (Vpre). Right atrial volume parameters were corrected by body surface area (VImax, VImin, VIpre). The total right atrial emptying fraction (RATEF), right atrial passive emptying fraction (RAPEF), right atrial active contraction emptying fraction (RAAEF) were calculated. The VVI data measuring right atrial global strain (RA-GLS), right atrial strain rate in ventricular systolic phase (RA-SRs), right atrial strain rate in ventricular early diastolic phase (RA-SRe), right atrial strain rate in ventricular late diastolic phase (RA-SRa).

Results

  1. 1.
    RA linear dimensions and volume parameters in severe OSAS were higher than those of control group. RAPEF in severe group was lower than control group and mild OSAS group (t?= 2.681, P?=?0.021; t?= 2.985, P?=?0.011; respectively). RAAEF in OSAS moderate group was higher than that of control group (t?= 3.006, P?=?0.02), and without statistical difference (P?>?0.05) in the severe OSAS group and the control group.
     
  2. 2.
    RA-GLS in moderate OSAS group was significantly lower than that of control group (t?= 2.333, P?=?0.040) and reduced more obvious in the severe OSAS group (vs control, t?= 3.25, P?=?0.008, vs mild; t?= 3.011, P?=?0.012; respectively). RA-SRe in moderate and severe OSAS groups were lower than control group (t?= 2.466, P?=?0.031; t?= 3.547, P?=?0.005; respectively). RA-SRs of OSAS in severe group was lower than that of control and mild groups (t?= 3.665, P?=?0.004; t?= 3.204, P?=?0.008; respectively). RA-SRa in severe OSAS group was lower than that of control group (t?= 2.425, P?=?0.034).
     
  3. 3.
    Multivariate regression analysis showed that RA-GLS and RA-SRe were independently correlated with AHI (t?=???2.738, P?=?0.010; t?=???2.191, P?=?0.036; respectively).
     

Conclusion

RA function was impaired in patients with OSAS. On hemodynamics, the change of RA function performed increased of reserve function, reduced pipeline function and increased of contraction function. However, the strain and strain rate reduced in different degree. RA-GLS and RA-SRe decreased the earliest, which suggested that strain and strain rate were the parameters which can reflect myocardial function damage earliest. VVI can more earlier and accurately detect myocardial dysfunction of right atrium in patients with OSAS, which is expected to be a worthy technique for early clinical therapy in patients with OSAS.
  相似文献   

13.
Kashin-Beck disease (KBD) is a chronic osteochondropathy. The genetic basis of KBD remains elusive now. To investigate the relationship between PPARGC1B gene polymorphism and KBD, we conducted a two-stage association study using 2743 unrelated Han Chinese subjects. In the first stage, three SNPs rs1078324, rs4705372, and rs11743128 of PPARGC1B gene were genotyped in 559 KBD patients and 467 health controls using Sequenom MassARRAY platform. In the second stage, the association analysis results of PPARGC1B with KBD were replicated using an independent sample of 1717 subjects. SNP association analysis was conducted by PLINK software. Genotype imputation was conducted by IMPUTE 2.0 against the reference panel of the 1000 genome project. Bonferroni multiple testing correction was performed. We observed a significant association signal at rs4705372 (P?=?0.0160) and a suggestive association signal at rs11743128 (P?=?0.0290). Further replication study confirmed the association signals of rs4705372 (P?=?0.0026) and rs11743128 (P?=?0.0387) in the independent validation sample. Our study results suggest that PPARGC1B is a novel susceptibility gene of KBD.  相似文献   

14.
The aim of the present study was to explore the role of lncRNA ANRIL in the pathogenesis of ischemic stroke (IS) and coronary artery disease (CAD) and to determine the association between ANRIL variants and the genetic susceptibility of IS and CAD in the Chinese Han population. A genetic association study including 550 IS patients, 550 CAD patients, and 550 healthy controls was conducted. The expression levels of lncRNA ANRIL, CDKN2A, and CDKN2B were detected using qRT-PCR. Genotyping was performed by Sequenom MassARRAY on an Agena platform. Our study showed that IS patients had an increased lncRNA ANRIL expression (P?=?0.002) and a decreased CDKN2A expression (P?<?0.001) compared with normal controls. A significant difference with regard to the genotype distribution of rs2383207 was found between male IS patients and controls (P?=?0.011). The minor allele of rs2383207 significantly increased the IS risk under a recessive model (OR?=?1.52, 95% CI?=?1.05–2.21, P?=?0.027). The minor allele of rs1333049 was significantly associated with the risk of IS among the male patients under a recessive model (OR?=?1.56, 95% CI?=?1.04–2.35, P?=?0.031). However, no significant association was found between the ANRIL variants and the risk of CAD (all P?>?0.050). In addition, we found a decreased lncRNA ANRIL expression in IS patients who carried the GG genotype of rs1333049 compared with IS patients who carried the CC or CG genotype (P?=?0.041). In summary, we found that IS patients had an increased lncRNA ANRIL expression and a decreased CDKN2A expression compared with the controls, which might play an impellent role in pathological processes of IS. The ANRIL variants rs2383207 and rs1333049 were significantly associated with the risk of IS among males but not females in the Chinese Han population.  相似文献   

15.

Background

In glomerular injury dendrin translocates from the slit diaphragm to the podocyte nucleus, inducing apoptosis. We analyzed dendrin expression in IgA glomerulonephritis and Henoch Schönlein purpura (IgAN/HSP) versus in podocytopathies minimal change disease (MCD) and focal segmental glomerulosclerosis (FSGS), and compared it to pathohistological findings and renal function at the time of biopsy and the last follow-up.

Methods

Twenty males and 13 females with median of age 35?years (min-max: 3–76) who underwent percutaneous renal biopsy and had diagnosis of glomerular disease (GD) were included in this retrospective study. Fifteen patients had IgAN/HSP and eighteen podocytopathy. Control group consisted of ten patients who underwent nephrectomy due to renal cancer. Dendrin expression pattern (membranous, dual, nuclear or negative), number of dendrin positive nuclei and proportion of dendrin negative glomeruli were analyzed.

Results

In GD and the control group significant differences in number of dendrin positive nuclei and proportion of dendrin negative glomeruli were found (P?=?0.004 and P?=?0.003, respectively). Number of dendrin positive nuclei was higher in podocytopathies than in IgAN/HSP, 3.90 versus 1.67 (P?=?0.028). Proportion of dendrin negative glomeruli correlated to higher rates of interstitial fibrosis (P?=?0.038), tubular atrophy (P?=?0.011) and globally sclerotic glomeruli (P?=?0.008). Dual and nuclear dendrin expression pattern were connected with lower rate of interstitial fibrosis and tubular atrophy than negative dendrin expression pattern (P?=?0.024 and P?=?0.017, respectively). Proportion of dendrin negative glomeruli correlated with lower creatinine clearance (CC) at the time of biopsy and the last follow-up (P?=?0.010 and P?<?0.001, respectively). Dendrin expression pattern correlated to CC at the last follow-up (P?=?0.009), being lower in patients with negative than nuclear or dual dendrin expression (P?=?0.034 and P?=?0.004, respectively).

Conclusion

In this pilot study the number of dendrin positive nuclei was higher in podocytopathies than in inflammatory GD. Negative dendrin expression pattern correlated to chronic tubulointerstitial changes and lower CC, which needs to be confirmed in a larger series.
  相似文献   

16.
Winter snowpack in seasonally snow-covered regions plays an important role in moderating ecosystem processes by insulating soil from freezing air temperatures. However, climate models project a decline in snowpack at mid and high latitudes over the next century. We conducted a snow removal experiment in a temperate deciduous forest at Harvard Forest in Massachusetts, USA to quantify the effects of a reduced winter snowpack and increased soil freezing on total soil respiration and its bulk (i.e. heterotrophic) and root-rhizosphere components. Snow removal increased soil freezing severity by more than three-fold, which resulted in a 27.6% increase in annual total soil respiration (p?=?0.058). Across our plots and years of this study, we found that the severity, rather than simply the presence of soil freezing, was the primary driver of the soil respiration response to reduced winter snowpack. Bulk soil respiration made the largest contribution to total soil respiration with root-rhizosphere respiration contributing up to 26.1?±?6.5% of total soil respiration across plot types and years. Snow removal significantly increased fine root mortality (p?=?0.03), which was positively correlated with soil frost depth and duration (p?=?0.068, \({\text{R}}_{{{\text{LMM}}(m)}}^{ 2}\)?=?0.46), rates of total soil respiration (p?=?0.075; \({\text{R}}_{{{\text{LMM}}(m)}}^{ 2}\)?=?0.27) and the contribution of root-rhizosphere respiration to total soil respiration (p?=?0.004; \({\text{R}}_{{{\text{LMM}}(m)}}^{ 2}\)?=?0.58). We conclude that increased rates of soil respiration in response to soil freezing are driven by plant-mediated processes, whereby soil frost-induced root mortality stimulates respiration through decomposition of root necromass with additional enhancements possibly related to priming of soil organic matter decomposition and elevated rates of root respiration associated with growth.  相似文献   

17.
There is accumulating evidence that the human leukocyte antigen (HLA) gene variants are associated with Alzheimer’s disease (AD). However, how they affect AD occurrence is still unknown. In this study, we firstly investigated the association of gene variants in HLA gene variants and brain structures on MRI in a large sample from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) to explore the effects of HLA on AD pathogenesis. We selected hippocampus, hippocampus CA1 subregion, parahippocampus, posterior cingulate, precuneus, middle temporal, entorhinal cortex, and amygdala as regions of interest (ROIs). According to the previous association studies of HLA variants and AD, 12 SNPs in HLA were identified in the dataset following quality control measures. In total group analysis, our results showed that TNF-α SNPs at rs2534672 and rs2395488 were significantly positively associated with the volume of the left middle temporal lobe (rs2534672: P?=?0.00035, Pc?=?0.004; rs2395488: P?=?0.0038, Pc?=?0.023) at baseline. In the longitudinal study, HFE rs1800562 was remarkably correlated with the lower atrophy rate of right middle temporal lobe (P?=?0.0003, Pc?=?0.003) and RAGE rs2070600 was associated with the atrophy rate of right hippocampus substructure-CA1 over 2 years (P?=?0.003, Pc?=?0.035). Furthermore, we detected the above four associations in mild cognitive impairment (MCI) subgroup analysis, as well as the association of rs2534672 with the baseline volume of the left middle temporal lobe in normal cognition (NC) subgroup analysis. Our study provided preliminary evidences that HLA gene variants might participate in the structural alteration of AD associated brain regions, hence modulating the susceptibility of AD.  相似文献   

18.

Introduction

Little is known about the association of urine metabolites with structural lesions in persons with diabetes.

Objectives

We examined the relationship between 12 urine metabolites and kidney structure in American Indians with type 2 diabetes.

Methods

Data were from a 6-year clinical trial that assessed renoprotective efficacy of losartan, and included a kidney biopsy at the end of the treatment period. Metabolites were measured in urine samples collected within a median of 6.5 months before the research biopsy. Associations of the creatinine-adjusted urine metabolites with kidney structural variables were examined by Pearson’s correlations and multivariable linear regression after adjustment for age, sex, diabetes duration, hemoglobin A1c, mean arterial pressure, glomerular filtration rate (iothalamate), and losartan treatment.

Results

Participants (n?=?62, mean age 45?±?10 years) had mean?±?standard deviation glomerular filtration rate of 137?±?50 ml/min and median (interquartile range) urine albumin:creatinine ratio of 34 (14–85) mg/g near the time of the biopsy. Urine aconitic and glycolic acids correlated positively with glomerular filtration surface density (partial r?=?0.29, P?=?0.030 and r?=?0.50, P?<?0.001) and total filtration surface per glomerulus (partial r?=?0.32, P?=?0.019 and r?=?0.43, P?=?0.001). 2-ethyl 3-OH propionate correlated positively with the percentage of fenestrated endothelium (partial r?=?0.32, P?=?0.019). Citric acid correlated negatively with mesangial fractional volume (partial r=-0.36, P?=?0.007), and homovanillic acid correlated negatively with podocyte foot process width (partial r=-0.31, P?=?0.022).

Conclusions

Alterations of urine metabolites may associate with early glomerular lesions in diabetic kidney disease.
  相似文献   

19.
Removal of corn (Zea mays L.) stover as a biofuel feedstock is being considered. It is important to understand the implications of this practice when establishing removal guidelines to ensure the long-term sustainability of both the biofuel industry and soil health. Aboveground and belowground plant residues are the soil’s main sources of organic materials that bind soil particles together into aggregates and increase soil carbon (C) storage. Serving to stabilize soil particles, soil organic matter (SOM) assists in supplying plant available nutrients, increases water holding capacity, and helps reduce soil erosion. Data obtained from three Corn Stover Regional Partnership sites (Brookings, SD; Morris, MN; and Ithaca, NE) were utilized to evaluate the impact of removing corn stover on soil physical properties, including dry aggregate size distribution (DASD), erodible fraction (EF), and SOM components. Each site consisted of a combination of three residue removal rates (low—removal of grain only, intermediate—approximately 50 % residue removal, and high—maximum amount of residue removal). Results showed that the distribution of soil aggregates was less favorable for all three locations when residue was removed without the addition of other sources of organic matter such as cover crops. Additionally, we found that when residue was removed and the soil surface was less protected, there was an increase in the EF at all three research sites. There was a reduction in the EF for both the Brookings, SD, and Ithaca, NE sites when cover crops were incorporated or additional nitrogen (N) was added to the system. Amounts of SOM, fine particulate organic matter (fPOM), and total particulate organic matter (tPOM) consistently decreased as greater amounts of residue were removed from the soil surface. Across these three locations, the removal of crop residue from the soil surface had a negative impact on measured soil physical properties. The addition of a cover crop or additional N helped reduce this impact as measured through aggregate size distribution and EF and SOM components.  相似文献   

20.
This research was conducted to distinguish between the separate effects of the Phanerochaete chrysosporium inoculation and sample property heterogeneity induced by different inoculation regimes on the indigenous bacterial communities during agricultural waste composting. P. chrysosporium was inoculated during different phases. The bacterial community abundance and structure were determined by quantitative PCR and denaturing gradient gel electrophoresis analysis, respectively. Results indicated a significant stimulatory effect of P. chrysosporium inoculation on the bacterial community abundance. The bacterial community abundance significantly coincided with pile temperature, ammonium, and nitrate (P?<?0.006). Variance partition analysis showed that the P. chrysosporium inoculation directly explained 20.5 % (P?=?0.048) of the variation in the bacterial communities, whereas the sample property changes induced by different inoculation regimes indirectly explained up to 35.1 % (P?=?0.002). The bacterial community structure was significantly related to pile temperature, water-soluble carbon (WSC), and C/N ratio when P. chrysosporium were inoculated. The C/N ratio solely explained 7.9 % (P?=?0.03) of the variation in community structure, whereas pile temperature and WSC explained 7.7 % (P?=?0.026) and 7.5 % (P?=?0.034) of the variation, respectively. P. chrysosporium inoculation affected the indigenous bacterial communities most probably indirectly through increasing pile temperature, enhancing the substrate utilizability, and changing other physico-chemical factors.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号