Parametric optimization and heat transfer analysis of a dual loop ORC (organic Rankine cycle) system for CNG engine waste heat recovery

In this study, a dual loop ORC (organic Rankine cycle) system is adopted to recover exhaust energy, waste heat from the coolant system, and intercooler heat rejection of a six-cylinder CNG (compressed natural gas) engine. The thermodynamic, heat transfer, and optimization models for the dual loop ORC system are established. On the basis of the waste heat characteristics of the CNG engine over the whole operating range, a GA (genetic algorithm) is used to solve the Pareto solution for the thermodynamic and heat transfer performances to maximize net power output and minimize heat transfer area. Combined with optimization results, the optimal parameter regions of the dual loop ORC system are determined under various operating conditions. Then, the variation in the heat transfer area with the operating conditions of the CNG engine is analyzed. The results show that the optimal evaporation pressure and superheat degree of the HT (high temperature) cycle are mainly influenced by the operating conditions of the CNG engine. The optimal evaporation pressure and superheat degree of the HT cycle over the whole operating range are within 2.5–2.9 MPa and 0.43–12.35 K, respectively. The optimal condensation temperature of the HT cycle, evaporation and condensation temperatures of the LT (low temperature) cycle, and exhaust temperature at the outlet of evaporator 1 are kept nearly constant under various operating conditions of the CNG engine. The thermal efficiency of the dual loop ORC system is within the range of 8.79%–10.17%. The dual loop ORC system achieves the maximum net power output of 23.62 kW under the engine rated condition. In addition, the operating conditions of the CNG engine and the operating parameters of the dual loop ORC system significantly influence the heat transfer areas for each heat exchanger

Ammonia Recovery from Digester Centrate with Electrochemical Membrane Systems: Mechanism, Performance, and Application

Nitrogen plays an indispensable role in living organisms and thus is a key element for agricultural production. Ammonia (NH3), as an important part in nitrogen cycle, can be synthesized by nitrogen fixing bacteria and the Haber-Bosch process, the latter of which requires an extensive energy input. Wastewaters can contain a large amount of nitrogen compounds because of kitchen and toilet wastes being discharged to sewage. The concentration of ammonia nitrogen (NH4+-N) can be hundreds mg per liter in some wastewaters like anaerobic digester (AD) centrate. However, both Haber-Bosch process and conventional wastewater ammonia treatment process are energy intensive, which making direct ammonia recovery from wastewater streams become increasingly beneficial in order to achieve sustainable nitrogen management. Electrochemical and membrane technology are emerging technologies that can achieve ammonia recovery with high recovery efficiency, while many of the those are still energy- and chemical-intensive. These motivate us to develop novel integrated membrane and electrochemical systems for ammonia recovery from wastewater. Meanwhile, the mechanisms and performance of the new systems should be investigated systematically through experiment and modeling, and the application of the recovery products also needs to be evaluated. To start with, a microbial electrochemical system (MES) was used to recover ammonia from a mixture of AD centrate and food wastewater at an optimal volume ratio of 3:1. The catholyte of the MES, which contained the recovered ammonia, was used to prepare fertilizers to support the growth of a model plant Arabidopsis thaliana. It was observed that A. thaliana grown on the MES generated fertilizer amended with extra potassium, phosphorus, and trace elements showed similar appearance to the control group that was added with a commercial fertilizer. RNA-Seq analyses were used to examine A. thaliana genetic responses to the MES generated fertilizers or the commercial counterpart. The comparative study offered metabolic insights into A. thaliana physiologies subject to the recovered nitrogen fertilizers. The results of this study have demonstrated the potential application of using the recovered ammonia from AD centrate as a nitrogen source in fertilizer. Next, a novel electrochemical membrane system (EMS) was developed to recover nitrogen from real AD centrate. The EMS synergistically coupled electrodialysis with membrane contactor to facilitate the selective recovery of target nutrient. Under a constant current of 10 mA cm-2, the EMS recovered more 80% of NH4+-N. The results of this study have demonstrated the feasibility of the proposed EMS and encouraged further investigation to reduce its energy consumption and improve nutrient recovery. Afterwards, a four-chamber electrochemical membrane system was developed to reduce the energy consumption and nutrient recovery cost. The lowest specific energy consumption of 8.2 ± 0.2 kWh kg-1 N was achieved under 1.25 mA cm-2. A preliminary cost analysis examined the relationship between acid price and dosage and estimated the operating cost of $0.58~0.83 kg-1N; simultaneously recovered phosphorus would further increase the benefit of this system. This work further studied the kinetics in different electrochemical systems to provide insights towards the operation and design of the system through mathematical modeling. Herein, we have performed Tafel analysis with Marcus-Hush-Chidsey (MHC) model for the first time to understand the anodic reaction kinetics in MES. After fitting the data over five months of cultivation, our results showed that MHC fitting curves can match better with a multi-electron transfer mechanism than with a one-electron transfer mechanism. To continue with, the kinetics of acid/base production, two important contributors to recover ammonia in the MES, was modeled with an empirical model by coupling MHC model and polynomial regression. When the EMS was fed with synthetic AD centrate, good fitting performance was achieved for both the anode and cathode half reactions. Moreover, the coupled model also showed decent prediction values when real AD centrate was fed into EMS if the bicarbonate concentration was included to modify the model. Challenges and opportunities were identified for using electrochemical and membrane technologies for ammonia recovery. It is recommended that long-term operation of the EMS to be conducted in order to evaluate the performance of the system after a few months, this would help to get a more comprehensive economic analysis of the cost to recover nutrients from AD centrate in EMS. Also, developing versatile functions of EMS together with ammonia recovery will uplevel its value, such as volatile fatty acid recovery, carbon capture and storage, heavy metals removal, etc. It is still challenging to enlarge the EMS to pilot-scale, but with the experiment and modeling work conducted in this dissertation, the path to a more sustainable cycle of nitrogen resources is smoother

Effects of canopy resistance parameterization on evapotranspiration partitioning and soil water contents in a maize field under a semiarid climate

Different canopy resistance (rc) parameterization has been used in land surface models to simulate actual evapotranspiration (ETc) and soil hydraulic variable for crop fields. However, the influence of rc parameterization on evapotranspiration (ET) partitioning and soil water dynamics has not been fully investigated with consideration of the coupled soil water and vapor physics. This study investigated the influential mechanisms of five rc methods (viz., Jarvis, Katerji-Perrier, Massman, Kelliher-Leuning, and Farias) on ET partitioning and soil water contents in an irrigated maize field under a semiarid climate through a soil water and vapor transfer model. The Jarvis method presented the best ET results (R2 = 0.86 and RMSE = 0.71 mm·d–1). Different rc parameterization mainly altered the simulated amount of soil water contents, while not changed the response of soil water dynamics to irrigation events. By the integrated analysis of the ET partitioning and root-zone water budget, different rc methods varied in the choice of the optimum irrigation water use strategies. This study identified the direct and indirect impacts of rc on the ET partitioning and emphasizes the necessity of both the ET partitioning and water supply sources in the decision-making for irrigation water management in semiarid regions.</p

Interval Type-2 Fuzzy Programming Method for Risky Multicriteria Decision-Making with Heterogeneous Relationship

We propose a new interval type-2 fuzzy (IT2F) programming method for risky multicriteria decision-making (MCDM) problems with IT2F truth degrees, where the criteria exhibit a heterogeneous relationship and decision-makers behave according to bounded rationality. First, we develop a technique to calculate the Banzhaf-based overall perceived utility values of alternatives based on 2-additive fuzzy measures and regret theory. Subsequently, considering pairwise comparisons of alternatives with IT2F truth degrees, we define the Banzhaf-based IT2F risky consistency index (BIT2FRCI) and the Banzhaf-based IT2F risky inconsistency index (BIT2FRII). Next, to identify the optimal weights, an IT2F programming model is established based on the concept that BIT2FRII must be minimized and must not exceed the BIT2FRCI using a fixed IT2F set. Furthermore, we design an effective algorithm using an external archive-based constrained state transition algorithm to solve the established model. Accordingly, the ranking order of alternatives is derived using the Banzhaf-based overall perceived utility values. Experimental studies pertaining to investment selection problems demonstrate the state-of-the-art performance of the proposed method, that is, its strong capability in addressing risky MCDM problems

T cell senescence: a new perspective on immunotherapy in lung cancer

T cell senescence is an indication of T cell dysfunction. The ability of senescent T cells to respond to cognate antigens is reduced and they are in the late stage of differentiation and proliferation; therefore, they cannot recognize and eliminate tumor cells in a timely and effective manner, leading to the formation of the suppressive tumor microenvironment. Establishing methods to reverse T cell senescence is particularly important for immunotherapy. Aging exacerbates profound changes in the immune system, leading to increased susceptibility to chronic, infectious, and autoimmune diseases. Patients with malignant lung tumors have impaired immune function with a high risk of recurrence, metastasis, and mortality. Immunotherapy based on PD-1, PD-L1, CTLA-4, and other immune checkpoints is promising for treating lung malignancies. However, T cell senescence can lead to low efficacy or unsuccessful treatment results in some immunotherapies. Efficiently blocking and reversing T cell senescence is a key goal of the enhancement of tumor immunotherapy. This study discusses the characteristics, mechanism, and expression of T cell senescence in malignant lung tumors and the treatment strategies

Glutaredoxin2 reduces age-associated B cell differentiation through maintaining redox homeostasis

BackgroundThe redox system plays a pivotal role in autoimmune diseases and cancer, with oxidative stress and antioxidant adaptations driving pathological processes. Age/autoimmunity-associated B cells (ABCs), characterized by elevated ROS levels, are implicated in autoimmune disorders such as systemic lupus erythematosus (SLE). However, the mechanisms linking ROS to ABC differentiation remain unclear. Glutaredoxin 2 (Grx2), a key oxidoreductase, regulates redox homeostasis, but its role in autoimmune B cell biology is underexplored.MethodsUsing wild-type and Grx2-knockout mice, we examined ROS levels and ABC differentiation. In vitro, ABC differentiation was induced with IL-21 and TLR7 agonist, and the effect of the antioxidant N-Acetyl-L-Cysteine (NAC) was assessed. The SLE-prone ShipΔB model crossed with Grx2−/− mice was used to evaluate autoimmune pathology.ResultsABCs exhibited higher ROS levels than follicular B cells, and NAC reduced ABC differentiation rate by 50%, demonstrating ROS dependency. Grx2 deficiency amplified ROS levels and ABC proportions in aged mice, correlating with accelerated autoimmunity. In ShipΔB mice, Grx2 deletion exacerbated ABC differentiation, CD4+ T cell activation, and anti-dsDNA autoantibody titers.ConclusionsGrx2 acts as a redox checkpoint that limits ABC-driven autoimmunity by modulating ROS. The Grx2–ROS axis represents a potential therapeutic target for SLE and related chronic inflammatory diseases

Identifying the Antiproliferative Effect of Astragalus Polysaccharides on Breast Cancer: Coupling Network Pharmacology With Targetable Screening From the Cancer Genome Atlas

Background:Astragalus polysaccharides (APS), natural plant compounds, have recently emerged as a promising strategy for cancer treatment, but little is known concerning their effects on breast cancer (BC) tumorigenesis.Methods: We obtained breast cancer genetic data from The Cancer Genome Atlas (TCGA) database, network pharmacology to further clarify its biological properties. Survival analysis and molecular docking techniques were implemented for the final screening to obtain key target information. Our experiments focused on the detection of intervention effects of APS on BC cells (MCF-7 and MDA-MB-231), and quantitative RT-PCR (qRT-PCR) was used to assess the expression of key targets.Results: A total of 1,439 differentially expressed genes (DEGs) were identified by TCGA and used to build disease networks. Module analysis, gene ontology and pathway analysis revealed characteristic of the DEGs network. Topological properties were used to identify key targets, survival analysis and molecular docking finally found that the targets of APS regulation of BC cells may be CCNB1, CDC6, and p53. Through cell viability, migration and invasion assays, we found that APS interferes with the development of breast cancer in MCF7 and MDA-MB-231 cells in a dose-dependent manner. Furthermore, qRT-PCR verification suggested that the expression of CCNB1 and CDC6 in breast cancer cells was significantly downregulated in response to APS, while expression of the tumor suppressor gene P53 was significantly increased.Conclusion: Results of this study suggest therapeutic potential for APS in BC treatment, possibly through interventions with CCNB1, CDC6, and P53. Furthermore, these findings illustrate the feasibility of using network pharmacology to connect large-scale target data as a way to discover the mechanism of natural products interfering with disease

Association between diabetes at different diagnostic ages and risk of cancer incidence and mortality: a cohort study

BackgroundDifferent ages for diagnosis of diabetes have diverse effects on risks of cardiovascular disease, dementia, and mortality, but there is little evidence of cancer. This study investigated the relationship between diabetes at different diagnostic ages and risks of cancer incidence and mortality in people aged 37–73 years.MethodsParticipants with diabetes in the UK Biobank prospective cohort were divided into four groups: ≤40, 41–50, 51–60, and &gt;60 years according to age at diagnosis. A total of 26,318 diabetics and 105,272 controls (1:4 randomly selected for each diabetic matched by the same baseline age) were included. We calculated the incidence density, standardized incidence, and mortality rates of cancer. Cox proportional hazard model was used to examine the associations of diabetes at different diagnostic ages with cancer incidence and mortality, followed by subgroup analyses.ResultsCompared to corresponding controls, standardized incidence and mortality rates of overall and digestive system cancers were higher in diabetes diagnosed at age 41–50, 51–60, and &gt;60 years, especially at 51–60 years. Individuals diagnosed with diabetes at different ages were at higher risk to develop site-specific cancers, with a prominently increased risk of liver cancer since the diagnosis age of &gt;40 years. Significantly, participants with diabetes diagnosed at 51–60 years were correlated with various site-specific cancer risks [hazard ratio (HR) for incidence: 1.088–2.416, HR for mortality: 1.276–3.269]. Moreover, for mortality of digestive system cancers, we observed an interaction effect between smoking and diabetes diagnosed at 51–60 years.ConclusionOur findings highlighted that the age at diagnosis of diabetes, especially 51–60 years, was critical risks of cancer incidence and mortality and may represent a potential preventative window for cancer

The Modulatory Properties of Astragalus membranaceus Treatment on Triple-Negative Breast Cancer: An Integrated Pharmacological Method.

Background: Studies have shown that the natural products of Astragalus membranaceus (AM) can effectively interfere with a variety of cancers, but their mechanism of action on breast cancer remains unclear. Triple-negative breast cancer (TNBC) is associated with a severely poor prognosis due to its invasive phenotype and lack of biomarker-driven-targeted therapies. In this study, the potential mechanism of the target composition acting on TNBC was explored by integrated pharmacological models and in vitro experiments. Materials and Methods: Based on the Gene Expression Omnibus (GEO) database and the relational database of Traditional Chinese Medicines (TCMs), the drug and target components were initially screened to construct a common network module, and multiattribute analysis was then used to characterize the network and obtain key drug-target information. Furthermore, network topology analysis was used to characterize the betweenness and closeness of key hubs in the network. Molecular docking was used to evaluate the affinity between compounds and targets and obtain accurate combination models. Finally, in vitro experiments verified the key component targets. The cell counting kit-8 (CCK-8) assay, invasion assay, and flow cytometric analysis were used to assess cell viability, invasiveness, and apoptosis, respectively, after Astragalus polysaccharides (APS) intervention. We also performed western blot analysis of key proteins to probe the mechanisms of correlated signaling pathways. Results: We constructed "compound-target" (339 nodes and 695 edges) and "compound-disease" (414 nodes and 6458 edges) networks using interaction data. Topology analysis and molecular docking were used as secondary screens to identify key hubs of the network. Finally, the key component APS and biomarkers PIK3CG, AKT, and BCL2 were identified. The in vitro experimental results confirmed that APS can effectively inhibit TNBC cell activity, reduce invasion, promote apoptosis, and then counteract TNBC symptoms in a dose-dependent manner, most likely by inhibiting the PIK3CG/AKT/BCL2 pathway. Conclusion: This study provides a rational approach to discovering compounds with a polypharmacology-based therapeutic value. Our data established that APS intervenes with TNBC cell invasion, proliferation, and apoptosis via the PIK3CG/AKT/BCL2 pathway and could thus offer a promising therapeutic strategy for TNBC

Development and external validation of dual online tools for prognostic assessment in elderly patients with high-grade glioma: a comprehensive study using SEER and Chinese cohorts

BackgroundElderly individuals diagnosed with high-grade gliomas frequently experience unfavorable outcomes. We aimed to design two web-based instruments for prognosis to predict overall survival (OS) and cancer-specific survival (CSS), assisting clinical decision-making.MethodsWe scrutinized data from the SEER database on 5,245 elderly patients diagnosed with high-grade glioma between 2000-2020, segmenting them into training (3,672) and validation (1,573) subsets. An additional external validation cohort was obtained from our institution. Prognostic determinants were pinpointed using Cox regression analyses, which facilitated the construction of the nomogram. The nomogram’s predictive precision for OS and CSS was gauged using calibration and ROC curves, the C-index, and decision curve analysis (DCA). Based on risk scores, patients were stratified into high or low-risk categories, and survival disparities were explored.ResultsUsing multivariate Cox regression, we identified several prognostic factors for overall survival (OS) and cancer-specific survival (CSS) in elderly patients with high-grade gliomas, including age, tumor location, size, surgical technique, and therapies. Two digital nomograms were formulated anchored on these determinants. For OS, the C-index values in the training, internal, and external validation cohorts were 0.734, 0.729, and 0.701, respectively. We also derived AUC values for 3-, 6-, and 12-month periods. For CSS, the C-index values for the training and validation groups were 0.733 and 0.727, with analogous AUC metrics. The efficacy and clinical relevance of the nomograms were corroborated via ROC curves, calibration plots, and DCA for both cohorts.ConclusionOur investigation pinpointed pivotal risk factors in elderly glioma patients, leading to the development of an instrumental prognostic nomogram for OS and CSS. This instrument offers invaluable insights to optimize treatment strategies