Labile soil organic carbon pools are valuable indicators of soil quality, early changes in soil total organic carbon (TOC) stocks, and (hence) changes in soil carbon sequestration pools and dynamics ...induced by changes in soil management practices. To improve the management of loess soils in China, we have examined effects of soil and nutrient management treatments applied in a 20-year experiment on TOC and the following fractions: particulate organic carbon (POC), light fraction organic carbon (LFOC), microbial biomass carbon (MBC) and permanganate oxidizable carbon (KMnO4 C). The soil management regimes were cropland abandonment (Abandonment), bare fallow without vegetation (Fallow) and a wheat-maize cropping system (Cropping). Cropping was combined with the following nutrient management treatments: control (CK, no nutrient input), nitrogen only (N), nitrogen and potassium (NK), phosphorus and potassium (PK), NP, NPK, straw plus NPK (SNPK) and two levels of manure (M, 13.7 and 20.6tha−1) plus NPK (M1NPK and M2NPK). After 20years, the Fallow treatment resulted in significantly lower TOC by 22% and labile C fractions by 29%–43% except MBC than Cropping, while Abandonment markedly increased all labile C fractions by 43%–64% except POC relative to Cropping, but the Abandonment and Cropping regimes resulted in similar TOC contents (10.75gkg−1 and 10.16gkg−1, respectively). Of the four C fractions, LFOC and KMnO4 C were the most sensitive indicators of changes in TOC induced by the soil management regimes. Under Cropping, TOC contents were similar in NP, NPK and SNPK plots, and significantly higher than those in CK plots (by 34%, 32% and 45%, respectively). Manure addition further enhanced TOC contents, which were highest following the M2NPK treatment (13.88gkg−1). Labile C fractions were also significantly higher following the treatments including organic amendment than following applications solely of chemical fertilizers, except that the SNPK, NP and NPK treatments resulted in similar LFOC contents. Application solely of chemical fertilizers had no significant effects on LFOC and KMnO4 C fractions compared with CK. Nevertheless, application of NP or NPK significantly increased contents of POC and MBC relative to CK (by 115% and 90% or 31% and 53%, respectively). Thus, LFOC and KMnO4 C fractions were not sensitive indicators of changes in TOC induced by mineral nutrient management practices under current conditions. Overall, given the minor differences between the effects of the NP and NPK treatments, application of manure and NP appears to be the most suitable management practice for improving TOC sequestration in the loess soil.
► Soil management regimes had significant effects on TOC and its fractions. ► Bare fallow resulted in significantly lower labile C fractions than Cropping. ► Abandonment markedly increased labile C fractions except POC relative to Cropping. ► Integrated application of manure and NPK greatly improved TOC and its labile pools.
•Published data on WUE of dryland maize in the Loess Plateau were analyzed.•The highest yield and WUE were under plastic mulching and the lowest in conventional practice.•The attainable WUE was ...40kgha−1mm−1 in the region.•The yield-ET relationship indicated that yield was limited by weather and management factors.•Mulching, cultivar selection, and canopy management need to be integrated for increasing WUE.
Owing to the critical situation of water resources and demographic pressure, improvement of crop water use efficiency (WUE=grain yield per unit seasonal evapotranspiration) in the dryland area of Loess Plateau of China is crucial. The aims of this study were (i) quantifying WUE of dryland maize (Zea mays L.) in the Loess Plateau, and (ii) identifying management practices that improve both WUE and yield. We compiled a data base of 36 sets of experiments spanning more than 20 years, where conventional practice (CT) was compared with alternatives including RT/NT, reduced or no tillage without straw mulching; SM, straw mulching; PM, plastic film mulching 100%; RM, plastic film mulching 50% or more; RMS, ridge mulched with plastic film+furrow mulched with crop straw.
Yield ranged from 1.12 to 14.6Mgha−1 and WUE from 2.8 to 39.0kgha−1mm−1; the maximum yield and WUE were achieved under RM, PM and RMS and the minimum under CT. Practices had small and inconsistent effect on seasonal evapotranspiration, hence variation in yield and WUE were attributable to changes in both the contribution of soil evaporation to total evapotranspiration and the partitioning of seasonal water use before and after silking. The yield-evapotranspiration relationship indicated that attainable WUE was 40kgha−1mm−1. Few crops, however, reached this efficiency emphasizing the opportunities for improvement. Implications for crop management and further improvement in yield and WUE are discussed.
Strain localization during tensile deformation of cold-rolled and annealed 7Mn steel were investigated under various strain rates and deformation temperatures. The retained austenite grain size, ...strain rate and deformation temperature all have remarkable influences on the appearance of PLC bands. Higher strain rate clearly suppressed the formation of PLC bands whilst deformation temperature had a more complicated influence. During the room-temperature deformation at the quasistatic strain rate of 6.67 × 10−4/s, Lüders bands appeared in all specimens whilst PLC bands only in the specimens that were annealed above 700 °C. Digital image correlation (DIC) analysis showed the specimen annealed at 700 °C exhibited the type A PLC bands during the entire period of deformation; whilst the one annealed at 720 °C showed the more complicated type A+B bands before 600s and the type A bands afterward. All of these phenomena have been discussed in relation to the interaction of C atoms/C-Mn pairs and dislocations for sound interpretation.
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•The examined medium-Mn steel exhibited either no or different types of PLC bands when annealed at various temperatures.•The occurrence of PLC band is determined by the grain size of retained austenite that controls dislocation density multiplied.•The stability of retained austenite grains determines the transformation rate and consequently governs the type of PLC band.•Both strain rate and deformation temperature have significant influences on the PLC effects.
The co-inhibitory receptor Programmed Death-1 (PD-1) curtails immune responses and prevent autoimmunity, however, tumors exploit this pathway to escape from immune destruction. The co-stimulatory ...receptor OX40 is upregulated on T cells following activation and increases their clonal expansion, survival and cytokine production when engaged. Although antagonistic anti-PD-1 or agonistic anti-OX40 antibodies can promote the rejection of several murine tumors, some poorly immunogenic tumors were refractory to this treatment. In the present study, we evaluated the antitumor effects and mechanisms of combinatorial PD-1 blockade and OX40 triggering in a murine ID8 ovarian cancer model. Although individual anti-PD-1 or OX40 mAb treatment was ineffective in tumor protection against 10-day established ID8 tumor, combined anti-PD-1/OX40 mAb treatment markedly inhibited tumor outgrowth with 60% of mice tumor free 90 days after tumor inoculation. Tumor protection was associated with a systemic immune response with memory and antigen specificity and required CD4(+) cells and CD8(+) T cells. The anti-PD-1/OX40 mAb treatment increased CD4(+) and CD8(+) cells and decreased immunosuppressive CD4(+)FoxP3(+) regulatory T (Treg) cells and CD11b(+)Gr-1(+) myeloid suppressor cells (MDSC), giving rise to significantly higher ratios of both effector CD4(+) and CD8(+) cells to Treg and MDSC in peritoneal cavity; Quantitative RT-PCR data further demonstrated the induction of a local immunostimulatory milieu by anti-PD-1/OX40 mAb treatment. The splenic CD8(+) T cells from combined mAb treated mice produced high levels of IFN-γ upon tumor antigen stimulation and exhibited antigen-specific cytolytic activity. To our knowledge, this is the first study testing the antitumor effects of combined anti-PD-1/OX40 mAb in a murine ovarian cancer model, and our results provide a rationale for clinical trials evaluating ovarian cancer immunotherapy using this combination of mAb.
▶ No-tillage combined with crop residue mulching was not recommended for spring maize cultivation in the study area. ▶ Ridges covered by plastic film combined with bare furrow may not sustain maize ...productivity in the long run. ▶ Ridges covered by plastic film combined with furrow mulched by crop residue could be a suitable measure for sustaining maize productivity and maintaining soil fertility.
The large dryland area of the Loess Plateau is subject of developing strategies for a sustainable crop production, e.g. by modifications of field management affecting soil water status and crop productivity. A three-year field experiment was conducted to investigate the effects of field management practices on soil water, maize development and yield on the Loess Plateau of China. The field management practices included traditional tillage (CK), no-till with crop residue mulch (SM), alternating ridges mulched with plastic film and bare furrows (PM) and alternating ridges mulched with plastic film and furrows mulched with crop residue (PSM). The soil water storage was higher under SM than the other treatments, except in the first half of the first maize growing season. Higher soil water stimulated maize growth, as indicated by a higher leaf area index and greater biomass accumulation, and thus the highest grain yield (7251
kg
ha
−1) and water use efficiency (2.41
kg
m
−3) in the first experimental season was recorded in SM plots. Maize growth and grain yield did not benefit in the other two seasons. Although soil water storage was similar between PM or PSM and CK treatments at sowing and harvest time, consistently better maize development and higher grain yield were observed through three seasons in PM and PSM plots. Under the PM and PSM treatments grain yield was 8–24% and 13–24% higher, respectively, than under the CK treatment, indicating that utilization of water and other resources was better under these treatments. However, significant soil water depletion in deeper (>100
cm) soil layers was detected at harvest time under PM compared with CK, implying that higher yields might not be sustained in the long run. In conclusion, crop residue mulching combined with no-tillage is not recommended for spring-sown maize system under these temperate climate conditions. Instead, use of ridges mulched with plastic film combined with crop residues in furrows may be an efficient measure to increase crop yield and maintain or improve soil fertility.
Understanding organic carbon (OC) sequestration in aggregates and OC stability under different fertilization practices is of key importance in improving soil quality and crop productivity and in ...mitigating the causes of climate change. A long-term field experiment established in 1990 was used to assess the influence of organic and inorganic fertilizers on aggregate-associated OC and its mineralization and on the SOC stock at a soil depth of 0–20cm under an intensive wheat-maize cropping system on Anthrosol in North China. The study involved three treatments: CK, control without fertilization; NPK, nitrogen (N), phosphorus (P) and potassium (K) fertilizers; MNPK, manure (M) combined with N, P and K fertilizers. Soil samples were collected and analyzed to determine the size distribution of aggregates, which were separated by dry sieving; the concentrations of OC and N in aggregates (>2, 0.25–2 and <0.25mm) and bulk soils; and respiration from aggregates and bulk soils in the 0–10 and 10–20cm layers after 21years. Fertilization did not affect the size distribution of aggregates in the surface soil layer, but there was a significant change in the subsurface layer in response to manure addition. Application of NPK and MNPK significantly and evenly augmented OC and N sequestration in the three aggregate classes tested. However, the OC mineralization rate was substantially higher in micro- than in macro-aggregates. Application of NPK and MNPK considerably increased OC mineralization in both aggregates and bulk soils; MNPK yielded the highest values. OC mineralization rates in bulk soils were comparable among the three treatments for the surface layer, but they increased in the subsurface layer because of adding manure. Overall, soils treated for 21years with NPK and MNPK showed increases in the OC pools in the top 20cm of 7.42 and 22.83MgCha−1, respectively, compared with the control treatment, and had average sequestration rates of 353 and 1087kgCha−1yr−1 respectively. Thus, appropriate application of NPK, alone or in combination with manure, can lead to improved OC sequestration by evenly augmenting aggregate-associated OC and providing the same degree of protection for OC in both macro-aggregates and micro-aggregates under a winter wheat-summer maize rotation on Anthrosol.
•Fertilization evenly augmented OC and N sequestration in all aggregates.•OC respiration rate was markedly higher in micro- than in macro-aggregates.•SOC respiration rates in bulk soil were same among treatments at 0–10cm layer.•SOC sequestration rates were 353kgCha−1yr−1 under NPK treatment.•SOC sequestration rates were 1087kgCha−1yr−1 under MNPK treatment.
Background/Aims: Elucidation of the molecular mechanisms underlying ovarian cancer (OC) cell invasion and migration may provide important evidence for developing efficient therapy. Recently, Matrix ...metalloproteinase (MMP) has been shown to be regulated by vascular endothelial growth factor family members, especially placental growth factor (PLGF), as a potential mechanism underlying cancer invasion. Here, we studied the molecular relationship between PLGF and MMP7 in the OC. Methods: We examined the levels of PLGF and MMP7 in the resected OC specimens and compared to paired adjacent non-tumor ovarian tissue. We also examined the correlation between PLGF and MMP7. We modified PLGF levels in a human OC cell line, OVCAR3, and analyzed the effects on MMP7. Prediction of microRNA (miRNA) binding to 3'-UTR of MMP7 mRNA was performed by bioinformatics analyses and confirmed by a dual luciferase reporter assay using miR-543-modifed OC cells. The levels of miR-543 were examined in the OC specimens, and the correlation between miR-543 and PLGF or MMP7 was performed. Results: PLGF and MMP7 both significantly increased in the OC specimens, compared to paired adjacent non-tumor ovarian tissue. PLGF significantly increased MMP7 in the OC cells at protein level, but not at mRNA level. In OC cells, PLGF significantly decreased the levels of miR-543, which suppressed the translation of MMP7 mRNA via 3'-UTR binding. In OC specimen, miR-543 significantly decreased, compared to paired adjacent non-tumor ovarian tissue. An inverse correlation was detected between the levels of miR-543 and PLGF or MMP7 in the OC specimens. Conclusion: MiR-543 inhibits translation of MMP7 through binding to the 3'-UTR of MMP7 mRNA in OC. PLGF suppresses miR-543, which activates MMP7-mediated cancer invasion.
Soil aggregation was studied in a 21-year experiment conducted on an Anthrosol. The soil management regimes consisted of cropland abandonment, bare fallow without vegetation and cropping system. The ...cropping system was combined with the following nutrient management treatments: control (CONTROL, no nutrient input); nitrogen, phosphorus and potassium (NPK); straw plus NPK (SNPK); and manure (M) plus NPK (MNPK). Compared with the CONTROL treatment, the abandonment treatment significantly increased the formation of large soil macroaggregates (>2 mm) and consequently improved the stability of aggregates in the surface soil layer due to enhancement of hyphal length and of soil organic matter content. However, in response to long-term bare fallow treatment aggregate stability was low, as were the levels of aggregating agents. Long term fertilization significantly redistributed macroaggregates; this could be mainly ascribed to soil organic matter contributing to the formation of 0.5-2 mm classes of aggregates and a decrease in the formation of the >2 mm class of aggregates, especially in the MNPK treatment. Overall, hyphae represented a major aggregating agent in both of the systems tested, while soil organic compounds played significantly different roles in stabilizing aggregates in Anthrosol when the cropping system and the soil management regimes were compared.
Observational studies have identified associations between smoking, alcohol use, body mass index (BMI), and the levels of vitamin D with primary biliary cholangitis (PBC). However, there was a lack ...of randomization control studies to estimate the causal relationship. This study was to investigate the causal estimates for the effects of those risk factors on PBC.
The genetic instrument variants were extracted from genome-wide association studies in European ancestry. Two-sample mendelian randomization (MR) and multivariable mendelian randomization were used to determine genetically causal estimates. Primary analyses consisted of random-effects and fix-mode inverse-variance-weighted methods, followed by secondary sensitivity analyses to verify the results.
Our study showed that BMI was a causal factor for PBC (OR 1.35; 95% CI=1.03-1.77;
=0.029). In addition, we found that serum vitamin D levels had a protective effect on PBC after adjusting for BMI (OR 0.51; 95% CI=0.32-0.84;
=0.007). However, we failed to identify evidence supporting that genetic causal effect of smoking and alcohol intake were associated with PBC in European countries.
Our results enriched findings from previous epidemiology studies and provided evidence from MR that serum vitamin D concentrations and BMI were independent causal factors for PBC, suggesting that ensuing vitamin D sufficiency and healthy lifestyles might be a cost-effective measure for early intervention for PBC.
Ovarian cancer (OC) is a common gynecological cancer and characterized by high metastatic potential. MicroRNAs (miRNAs, miRs) have the promise to be harnessed as prognostic and therapeutic biomarkers ...for OC. Herein, we sought to identify differentially expressed miRNAs and mRNAs in metastatic OC, and to validate them with functional experiments.
Differentially expressed miRNAs and mRNAs were screened from six pairs of primary OC tissues and metastatic tissues using a miRStar™ Human Cancer Focus miRNA and Target mRNA PCR Array. Then, gene expression profiling results were verified by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and western blot assays. The binding affinity between miR-7-5p and TGFβ2 was validated by dual-luciferase reporter assay. Expression of miR-7-5p and TGFβ2 was manipulated to assess their roles in malignant phenotypes of highly metastatic HO-8910PM cells.
MiRNA profiling and sequencing identified 12 miRNAs and 10 mRNAs that were differentially expressed in metastatic tissues. Gene ontology and Pathway analyses determined that 3 differentially expressed mRNAs (ITGB3, TGFβ2 and TNC) were related to OC metastasis. The results of RT-qPCR confirmed that the decrease of miR-7-5p was most significant in OC metastasis, while TGFβ2 was up-regulated in OC metastasis. Moreover, miR-7-5p targeted and negatively regulated TGFβ2. MiR-7-5p overexpression accelerated HO-8910PM cell viability and invasion, and TGFβ2 overexpression reversed the results. Meanwhile, simultaneous miR-7-5p and TGFβ2 overexpression rescued the cell activities.
This study characterizes differentially expressed miRNAs and mRNAs in metastatic OC, where miR-7-5p and its downstream target were most closely associated with metastatic OC. Overexpression of miR-7-5p targets and inhibits TGFβ2 expression, thereby inhibiting the growth and metastasis of OC.
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