152 research outputs found

    Determination of safe operation zone for an intermediate-temperature solid oxide fuel cell and gas turbine hybrid system

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    This paper proposes a novel approach to determine the safe zone for an intermediate-temperature solid oxide fuel cell and gas turbine hybrid system. The approach first ensures the compressor safety and then determines the overall system safe zone by analyzing the unsafe characteristics of main components. Safe performance of the hybrid system fueled with biomass gas at all operations is analyzed. Finally, the map of safe zone is obtained to avoid component malfunctions and system performance deterioration. Results show that the hybrid system can achieve a high efficiency 60.78%, which is an interesting reference for distributed power stations. Under all operations, two unbalanced energy zones exist, which may cause the short supply of O2 or fuel for electrochemical reaction. The lower the rotational speed of gas turbine, the narrower the zone of carbon deposition takes place in the reformer or turbine inoperation caused by too low inlet temperature. However, the phenomenon of fuel cell thermal cracking due to over-temperature will be exacerbated. System layout also affects component safety especially for the fuel cell. In the safe zone, the system has a characteristic of high efficiency and low load with low rotational speed, vice versa. In other words, the powers and load adjustment ranges both decrease with decreasing rotational speed whereas the efficiency increases, which peaks at 63.43%.</p

    Effect of gasified biomass fuel on load characteristics of an intermediate-temperature solid oxide fuel cell and gas turbine hybrid system

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    This work uses the mathematical model of an intermediate-temperature solid oxide fuel cell and gas turbine (IT-SOFC/GT) hybrid system to study the effects of gasified biomass fuels on system load characteristics. The system performance is investigated by using four types of fuels in each adjusting mode. The relation between the fuel type and load adjusting mode is obtained for users and designers to select the appropriate fuel for reasonable operation modes. Results show that the hybrid system of 182.4 kW has a high electric efficiency of 60.78% by using wood chip gas (WCG). If cotton wood gas (CWG) and corn stalk gas (CSG) are used, both boundary values of steam to carbon ratio (S/Cbv) and system power are higher, but system efficiencies decrease to 57.36% and 57.87% respectively. In the designed three load adjusting modes, the system can reach maximum efficiency over 59% with four types of biomass gases. If high efficiency and a wide range of load adjustment are required, users can select Case B to use fuels like WCG and GSG. When higher efficiency and low load is expected, Case A is more desirable. With fuels like CWG and CSG, the system has good safety performance in Case C.</p

    Switchable counterion gradients around charged metallic nanoparticles enable reception of radio waves

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    Mechanically flexible, easy-to-process, and environmentally benign materials capable of current rectification are interesting alternatives to &quot;hard&quot; silicon-based devices. Among these materials are metallic/charged-organic nanoparticles in which electronic currents though metal cores are modulated by the gradients of counterions surrounding the organic ligands. Although layers of oppositely charged particles can respond to both electronic and chemical signals and can function even under significant mechanical deformation, the rectification ratios of these &quot;chemoelectronic&quot; elements have been, so far, low. This work shows that significantly steeper counterion gradients and significantly higher rectification ratios can be achieved with nanoparticles of only one polarity but in contact with a porous electrode serving as a counterion &quot;sink.&quot; These composite structures act as rectifiers even at radio frequencies, providing a new means of interfacing counterions&apos; dynamics with high-frequency electronic currents

    CDCA2 Inhibits Apoptosis and Promotes Cell Proliferation in Prostate Cancer and Is Directly Regulated by HIF-1α Pathway.

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    Prostate cancer (PCa) is a major serious malignant tumor and is commonly diagnosed in older men. Identification of novel cancer-related genes in PCa is important for understanding its tumorigenesis mechanism and developing new therapies against PCa. Here, we used RNA sequencing to identify the specific genes, which are upregulated in PCa cell lines and tissues. The cell division cycle associated protein (CDCA) family, which plays a critical role in cell division and proliferation, is upregulated in the PCa cell lines of our RNA-Sequencing data. Moreover, we found that CDCA2 is overexpressed, and its protein level positively correlates with its histological grade, clinical stage, and Gleason Score. CDCA2 was further found to be upregulated and correlated with poor prognosis and patient survival in multiple cancer types in The Cancer Genome Atlas (TCGA) dataset. The functional study suggests that inhibition of CDCA2 will lead to apoptosis and lower proliferation in vitro. Silencing of CDCA2 also repressed tumor growth in vivo. Loss of CDCA2 affects several oncogenic pathways, including MAPK signaling. In addition, we further demonstrated that CDCA2 was induced in hypoxia and directly regulated by the HIF-1α/Smad3 complex. Thus, our data indicate that CDCA2 could act as an oncogene and is regulated by hypoxia and the HIF-1αpathway. CDCA2 may be a useful prognostic biomarker and potential therapeutic target for PCa

    Association between extremely high-density lipoprotein cholesterol and adverse cardiovascular outcomes: a systematic review and meta-analysis

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    BackgroundThe association between high-density lipoprotein cholesterol (HDL-C) and adverse cardiovascular outcomes is understudied. Based on cohort studies, the current study aimed to investigate the association of extremely high HDL-C with all-cause, atherosclerotic cardiovascular disease (CVD) mortality, and stroke risk.MethodsA systematic literature search in Embase, PubMed, Cochrane Library, and Web of Science was performed to collect relevant cohort studies published before August 20, 2022. A random-effects model was used to pool relative risks (RRs) and 95% confidence intervals (CIs).ResultsA total of 17 cohort studies involving 19,630,829 participants were included, encompassing 18,547,132 total deaths (1,328,036 CVD deaths). All-cause mortality, CVD mortality, and stroke risk in the extremely high HDL-C group were increased by 15% (RR = 1.15, 95% CI:1.05–1.25), 14% (RR = 1.14, 95% CI:0.96–1.35) and 14% (RR = 1.14, 95% CI:0.82–1.58), compared to the normal HDL-C group. In subgroup analyses, extremely high HDL-C was associated with a reduced risk of CVD mortality in women and a lower risk of stroke in men compared to normal HDL-C levels.ConclusionsThe extremely high levels of HDL-C were associated with elevated risks of all-cause mortality, CVD mortality, and stroke. More well-designed studies are needed to confirm our findings.Systematic Review Registrationhttps://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=370201, identifier: CRD42022370201

    TfR1 binding with H-ferritin nanocarrier achieves prognostic diagnosis and enhances the therapeutic efficacy in clinical gastric cancer

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    H-ferritin (HFn) nanocarrier is emerging as a promising theranostic platform for tumor diagnosis and therapy, which can specifically target tumor cells via binding transferrin receptor 1 (TfR1). This led us to investigate the therapeutic function of TfR1 in GC. The clinical significance of TfR1 was assessed in 178 GC tissues by using a magneto-HFn nanoparticle-based immunohistochemistry method. The therapeutic effects of doxorubicin-loaded HFn nanocarriers (HFn-Dox) were evaluated on TfR1-positive GC patient-derived xenograft (GC-PDX) models. The biological function of TfR1 was investigated through in vitro and in vivo assays. TfR1 was upregulated (73.03%) in GC tissues, and reversely correlated with patient outcome. TfR1-negative sorted cells exhibited tumor-initiating features, which enhanced tumor formation and migration/invasion, whereas TfR1-positive sorted cells showed significant proliferation ability. Knockout of TfR1 in GC cells also enhanced cell invasion. TfR1-deficient cells displayed immune escape by upregulating PD-L1, CXCL9, and CXCL10, when disposed with IFN-γ. Western blot results demonstrated that TfR1-knockout GC cells upregulated Akt and STAT3 signaling. Moreover, in TfR1-positive GC-PDX models, the HFn-Dox group significantly inhibited tumor growth, and increased mouse survival, compared with that of free-Dox group. TfR1 could be a potential prognostic and therapeutic biomarker for GC: (i) TfR1 reversely correlated with patient outcome, and its negative cells possessed tumor-aggressive features; (ii) TfR1-positive cells can be killed by HFn drug nanocarrier. Given the heterogeneity of GC, HFn drug nanocarrier combined with other therapies toward TfR1-negative cells (such as small molecules or immunotherapy) will be a new option for GC treatment
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