586 research outputs found
Elevated CO2 and Warming Altered Grassland Microbial Communities in Soil Top-Layers.
As two central issues of global climate change, the continuous increase of both atmospheric CO2 concentrations and global temperature has profound effects on various terrestrial ecosystems. Microbial communities play pivotal roles in these ecosystems by responding to environmental changes through regulation of soil biogeochemical processes. However, little is known about the effect of elevated CO2 (eCO2) and global warming on soil microbial communities, especially in semiarid zones. We used a functional gene array (GeoChip 3.0) to measure the functional gene composition, structure, and metabolic potential of soil microbial communities under warming, eCO2, and eCO2 + warming conditions in a semiarid grassland. The results showed that the composition and structure of microbial communities was dramatically altered by multiple climate factors, including elevated CO2 and increased temperature. Key functional genes, those involved in carbon (C) degradation and fixation, methane metabolism, nitrogen (N) fixation, denitrification and N mineralization, were all stimulated under eCO2, while those genes involved in denitrification and ammonification were inhibited under warming alone. The interaction effects of eCO2 and warming on soil functional processes were similar to eCO2 alone, whereas some genes involved in recalcitrant C degradation showed no significant changes. In addition, canonical correspondence analysis and Mantel test results suggested that NO3-N and moisture significantly correlated with variations in microbial functional genes. Overall, this study revealed the possible feedback of soil microbial communities to multiple climate change factors by the suppression of N cycling under warming, and enhancement of C and N cycling processes under either eCO2 alone or in interaction with warming. These findings may enhance our understanding of semiarid grassland ecosystem responses to integrated factors of global climate change
What could the entire cornstover contribute to the enhancement of waste activated sludge acidification? Performance assessment and microbial community analysis
The growing inequality between firms
Globalisation, technological progress and a range of policies and institutions are driving ‘Great Divergences’ in wages and productivity, write Giuseppe Berlingieri, Patrick Blanchenay and Chiara Criscuol
Optimisation of wastewater treatment strategies in eco-industrial parks:Technology, location and transport
The expanding population and rapid urbanisation, in particular in the Global South, are leading to global challenges on resource supply stress and rising waste generation. A transformation to resource-circular systems and sustainable recovery of carbon-containing and nutrient-rich waste offers a way to tackle such challenges. Eco-industrial parks have the potential to capture symbioses across individual waste producers, leading to more effective waste-recovery schemes. With whole-system design, economically attractive approaches can be achieved, reducing the environmental impacts while increasing the recovery of high-value resources. In this paper, an optimisation framework is developed to enable such design, allowing for wide ranging treatment options to be considered capturing both technological and financial detail. As well as technology selection, the framework also accounts for spatial aspects, with the design of suitable transport networks playing a key role. A range of scenarios are investigated using the network, highlighting the multi-faceted nature of the problem. The need to incorporate the impact of resource recovery at the design stage is shown to be of particular importance
Optimal control towards sustainable wastewater treatment plants based on multi-agent reinforcement learning
Wastewater treatment plants are designed to eliminate pollutants and
alleviate environmental pollution. However, the construction and operation of
WWTPs consume resources, emit greenhouse gases (GHGs) and produce residual
sludge, thus require further optimization. WWTPs are complex to control and
optimize because of high nonlinearity and variation. This study used a novel
technique, multi-agent deep reinforcement learning, to simultaneously optimize
dissolved oxygen and chemical dosage in a WWTP. The reward function was
specially designed from life cycle perspective to achieve sustainable
optimization. Five scenarios were considered: baseline, three different
effluent quality and cost-oriented scenarios. The result shows that
optimization based on LCA has lower environmental impacts compared to baseline
scenario, as cost, energy consumption and greenhouse gas emissions reduce to
0.890 CNY/m3-ww, 0.530 kWh/m3-ww, 2.491 kg CO2-eq/m3-ww respectively. The
cost-oriented control strategy exhibits comparable overall performance to the
LCA driven strategy since it sacrifices environmental bene ts but has lower
cost as 0.873 CNY/m3-ww. It is worth mentioning that the retrofitting of WWTPs
based on resources should be implemented with the consideration of impact
transfer. Specifically, LCA SW scenario decreases 10 kg PO4-eq in
eutrophication potential compared to the baseline within 10 days, while
significantly increases other indicators. The major contributors of each
indicator are identified for future study and improvement. Last, the author
discussed that novel dynamic control strategies required advanced sensors or a
large amount of data, so the selection of control strategies should also
consider economic and ecological conditions
Control of the Power Flows of a Stochastic Power System
How to determine the power supply of a power system to guarantee that the
state remains during a short horizon in a critical subset of the state set? The
critical subset is related to the power flows of all power lines of a power
system and to transient stability. The control objective is to minimize a cost
function. That function is defined as the maximal power flow over all power
lines, including a multiple of its standard deviation, as a function of the
power supply vector. That the controlled system has an improved performance is
shown by numerical results of three academic examples including an eight-node
academic network, a twelve-node ring network, and a Manhattan-grid network.Comment: A supplement with 20 pages, 5 figures, 43 tables has been added to
the original manuscrip
Electron Fluxes in Biocathode Bioelectrochemical Systems Performing Dechlorination of Chlorinated Aliphatic Hydrocarbons
Bioelectrochemical systems (BESs) are regarded as a promising approach for the enhanced dechlorination of chlorinated aliphatic hydrocarbons (CAHs). However, the electron distribution and transfer considering dechlorination, methanogenesis, and other bioprocesses in these systems are little understood. This study investigated the electron fluxes in biocathode BES performing dechlorination of three typical CAHs, 1,1,2,2-tetrachloroethene (PCE), 1,1,2-trichloroethene (TCE) and 1,2-dichloroethane (1,2-DCA). Anaerobic sludge was inoculated to cathode and biocathode was acclimated by the direct acclimation and selection. The constructed biocathode at −0.26 V had significantly higher dechlorination efficiency (E24h > 99.0%) than the opened circuit (E24h of 17.2–27.5%) and abiotic cathode (E24h of 5.5–10.8%), respectively. Cyclic voltammetry analysis demonstrated the enhanced cathodic current and the positive shift of onset potential in the cathodic biofilm. Under autotrophic conditions with electrons from the cathode as sole energy source (columbic efficiencies of 80.4–90.0%) and bicarbonate as sole carbon source, CAHs dechlorination efficiencies were still maintained at 85.0 ± 2.0%, 91.4 ± 1.8%, and 84.9 ± 3.1% for PCE, TCE, and 1,2-DCA, respectively. Cis-1,2-dichloroethene was the final product for PCE and TCE, while 1,2-DCA went through a different dechlorination pathway with the non-toxic ethene as the final metabolite. Methane was the main by-product of the heterotrophic biocathode, and methane production could be enhanced to some extent by electrochemical stimulation. The various electron fluxes originating from the cathode and oxidation of organic substrates might be responsible for the enhanced CAHs dechlorination, while methane generation and bacterial growth would probably reduce the fraction of electrons provided for CAH dechlorination. The study deals with the dechlorination and competitive bioprocesses in CAH-dechlorinating biocathodes with a focus on electron fluxes
Central nervous system toxicity of metallic nanoparticles
Nanomaterials (NMs) are increasingly used for the therapy, diagnosis, and monitoring of disease- or drug-induced mechanisms in the human biological system. In view of their small size, after certain modifications, NMs have the capacity to bypass or cross the blood–brain barrier. Nanotechnology is particularly advantageous in the field of neurology. Examples may include the utilization of nanoparticle (NP)-based drug carriers to readily cross the blood–brain barrier to treat central nervous system (CNS) diseases, nanoscaffolds for axonal regeneration, nanoelectromechanical systems in neurological operations, and NPs in molecular imaging and CNS imaging. However, NPs can also be potentially hazardous to the CNS in terms of nano-neurotoxicity via several possible mechanisms, such as oxidative stress, autophagy, and lysosome dysfunction, and the activation of certain signaling pathways. In this review, we discuss the dual effect of NMs on the CNS and the mechanisms involved. The limitations of the current research are also discussed
Case Report: Proximal bronchial injury in small-cell lung cancer patient after moderately hypofractionated radiotherapy
BackgroundProximal bronchial injury is a frequently observed complication in patients with central lung cancer following high-dose stereotactic body radiotherapy, whereas it is rarely reported after moderately hypofractionated radiotherapy. In this article, we present a case of proximal bronchial injury in a patient with small-cell lung cancer after moderately hypofractionated radiotherapy.Case presentationA 45-year-old male patient with no history of smoking was diagnosed with limited stage small-cell lung cancer. According to guidelines of the National Comprehensive Cancer Network, the patient was treated with chemoradiotherapy, which included etoposide and cisplatin as well as radiotherapy at a dose of 65 Gy/26 fractions. Three months after radiotherapy, the tumor disappeared; however, stenosis of the right main bronchus, right upper lobe bronchus, and intermediate bronchus, as well as atelectasis of the right upper and middle lobes, occurred and gradually worsened. Anti-infection and hormonal therapy were ineffective. One year after radiotherapy, grade 3 damage was formed in the proximal bronchus according to the Common Terminology Criteria for Adverse Events (version 5.0). Following endoscopic balloon dilatation of the right main bronchus, asthma symptoms of the patient were reduced.ConclusionThis case reminds us that it is necessary to implement a proximal bronchial dose constraint and prevent the occurrence of dose hot spot in the proximal bronchus when administering moderately hypofractionated radiotherapy with a physical dose exceeding 65 Gy
Prognostic significance of peripheral CD8+CD28+ and CD8+CD28- T cells in advanced non-small cell lung cancer patients treated with chemo(radio)therapy.
peer reviewed[en] BACKGROUND: Noninvasive prognostic biomarkers are needed for advanced non-small cell lung cancer (NSCLC) patients with different histological types to identify cases with poor survival. Here, we investigated the prognostic values of peripheral CD8+CD28+ T cells and CD8+CD28- T cells in advanced NSCLC patients treated with chemo(radio)therapy and the impact of histological type on them.
METHODS: Of 232 registered advanced NSCLC patients, 101 treatment-naïve individuals were eligible and included in our study. Flow cytometry was used to evaluate CD8+CD28+ T cells, CD8+CD28- T cells, CD4+ CD25hi T cells, B cells, natural killer cells, γδT cells, and natural killer T cells in patients' peripheral blood.
RESULTS: The median follow-up time was 13.6 months. Fifty-nine (58.4%) patients died by the end of our study. Fifty-three of the 101 advanced NSCLC cases selected for our study were adenocarcinomas (ADs), and 48 were squamous cell carcinomas (SCCs). Multivariate analyses showed that increased levels of CD8+CD28+ T cells independently predicted favorable overall survival (OS) [hazard ratio (HR): 0.51, 95% confidence interval (CI) 0.30-0.89, P = 0.021] and progression-free survival (PFS) (HR: 0.66, 95% CI 0.37-0.93, P = 0.038) in ADs, but the prediction in SCCs was not statistically significant. In contrast, high levels of CD8+CD28- T cells independently predicted unfavorable OS (HR: 1.41, 95% CI 1.17-3.06, P = 0.035) and PFS (HR: 2.01, 95% CI 1.06-3.85, P = 0.029) in SCCs, but the prediction in ADs was not statistically significant. ADs had higher levels of CD4+CD25hi T cells and CD8+CD28- T cells and lower NK cells (all P < 0.05) than SCCs.
CONCLUSIONS: Our findings uncovered the prognostic values of peripheral CD8+CD28+ T cells and CD8+CD28- T cells in advanced NSCLC patients treated with chemo(radio)therapy, which could help to identify patients with poor outcomes and refine treatment strategies
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