•Integrated simulation framework consisting of COMSOL and Simulink models.•Hydrogen supply stability and recovery performance of a PEMFC system.•A lower ejector temperature is disadvantageous in ...removing the moisture content.•Passive Venturi ejector to perform hydrogen recovery significantly reduces the time required.
In traditional PEM fuel cells (PEMFCs), the unreacted hydrogen gas at the anode outlet is recovered using a mechanical pump or centrifuge and returned to the inlet side for reuse. However, the energy consumed by the pump reduces the system efficiency. Accordingly, the present study considers a 3-kW PEMFC in which the unreacted hydrogen gas is recovered passively from the exhaust stream using a Venturi ejector. An integrated simulation framework is constructed consisting of a COMSOL model of the ejector unit and a MATLAB/Simulink model of the hydrogen recovery system. The simulation framework is used to examine the temperature, pressure and velocity distributions within the ejector for various values of the inlet hydrogen pressure. The stability of the hydrogen supply in PEMFC systems incorporating a passive ejector system and a traditional mechanical hydrogen recovery system, respectively, is then investigated and compared. It is shown that the ejector stabilizes the hydrogen supply more quickly than the traditional mechanical system. As a result, it not only improves the hydrogen utilization rate and environmental safety of the PEMFC system, but also reduces the overall hydrogen consumption. The simulation results for the I-V performance of the PEMFC with the Venturi ejector are shown to be in good qualitative agreement with the experimental results. Overall, the numerical framework constructed in the present study provides a useful tool for exploring the effects of the ejector design parameters on the hydrogen recovery performance and determining the operating conditions which maximize the performance of the PEMFC system.
Increasing frequency of human exposure to PEG-related products means that healthy people are likely to have pre-existing anti-PEG antibodies (pre-αPEG Ab). However, the influence of pre-αPEG Abs on ...the pharmacokinetics (PK) and therapeutic efficacy of LipoDox is unknown.
We generated two pre-αPEG Ab mouse models. First, naïve mice were immunized with PEGylated protein to generate an endogenous αPEG Ab titer (endo αPEG). Second, monoclonal αPEG Abs were passively transferred (αPEG-PT) into naïve mice to establish a αPEG titer. The naïve, endo αPEG and αPEG-PT mice were intravenously injected with
in-labeled LipoDox to evaluate its PK. Tumor-bearing naïve, endo αPEG and αPEG-PT mice were intravenously injected with
in-labeled LipoDox to evaluate its biodistribution. The therapeutic efficacy of LipoDox was estimated in the tumor-bearing mice.
The areas under the curve (AUC)
of LipoDox in endo αPEG and αPEG-PT mice were 11.5- and 15.6- fold less, respectively, than that of the naïve group. The biodistribution results suggested that pre-αPEG Ab can significantly reduce tumor accumulation and accelerate blood clearance of
In-labeled LipoDox from the spleen. The tumor volumes of the tumor-bearing endo αPEG and αPEG-PT mice after treatment with LipoDox were significantly increased as compared with that of the tumor-bearing naïve mice.
Pre-αPEG Abs were found to dramatically alter the PK and reduce the tumor accumulation and therapeutic efficacy of LipoDox. Pre-αPEG may have potential as a marker to aid development of personalized therapy using LipoDox and achieve optimal therapeutic efficacy.
Late Paleozoic sedimentary strata outcrop extensively in central Inner Mongolia, and are a key to understanding the tectonic evolution of the southeastern Central Orogenic Belt. A combined analysis ...of petrography, whole-rock major and trace element, and Nd isotope is carried out on representative sandstones from the Late Paleozoic sedimentary strata (420–270 Ma). The sandstones are mainly wackes and litharenites in lithology, with low SiO2/Al2O3 of 2.85–9.47 (averagely 5.22) and poor textural and compositional maturities, implying short sediment transportation between the depositional basins and provenances. The trace element compositions are generally comparable to that of the average upper continent crust (UCC), with negatively-sloping chondrite-normalized rare earth element distribution patterns ((La/Yb)N = 3.43–11; averagely 6.94) and flat UCC-normalized trace element distribution patterns. The Nd isotopic compositions show great variation (ԐNd(t) = −5.01 to 5.35) with depositional time of the sandstones, and coincide well with the arc magmatic phases in central Inner Mongolia. The geochemical signatures of the sandstones indicate that the dominant provenances are intermediate to felsic arc magmatic rocks that have ages approximating the deposition, although old, recycled sediments may have made a minor contribution. An active continental arc setting during the Late Paleozoic in central Inner Mongolia, controlled by the northward subduction of the Paleo-Asian oceanic slab, was the most likely depositional tectonic setting of the sandstones. This active continental arc setting continued to at least 270 Ma, implying that the final closure of the Paleo-Asian Ocean along the Solonker suture zone most likely occurred sometime during the Late Permian to Early Triassic. The northward subduction of the Paleo-Asian Ocean is likely of West Pacific-style, in which the present-day Baolidao arc has a close genetic link with the South Mongolian microcontinent and, likely, the former originally formed as the arc margin of the latter.
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•First reported Nd isotope on Late Paleozoic sandstones in central Inner Mongolia•A dominant arc provenance and tectonic setting of the sandstones are proposed.•A west Pacific-style northward subduction of Paleo-Asian Ocean continued to 270 Ma.
•Effect of N2O decomposition on soot formation in N2O/C2H4 flame was examined.•Thermal effect of N2O decomposition on soot formation increased with the R value.•The oxy-enrichment effect on soot ...formation increased gradually.•Soot formation and oxidation rate rebalances under the N2O decomposition effect.
This study experimentally investigated the effect of nitrous oxide (N2O) decomposition on soot formation in N2O/ethylene diffusion flames. The effect of N2O decomposition on the soot formation mechanism was examined in three oxidation cases (Cases Case I–III). In Case I, N2O was used as the oxidant; in Case II, an oxygen-enriched N2/O2 mixture (67 % N2 + 33 % O2) was used as the oxidant; and in Case III, standard air (79 % N2 + 21 % O2) was used as the oxidant. A triple-port burner was used to generate diffusion flames with various R (ratio of the oxidizer flow velocity to the fuel flow velocity) values (R = 0–6). The soot concentration was measured through laser-induced incandescence, and the soot temperature was determined using two-color pyrometry. The measured soot temperatures increased significantly due to the thermal effect in the upstream position of the N2O/C2H4 flames. The oxygen-enrichment effect on soot formation increased gradually from 10 % to 60 % as R increased from 0.5 to 6. The integration of the soot concentration along the flame length revealed that the soot formation rate and soot oxidation rate might rebalance under the N2O decomposition effect.
Astrocyte and microglia activation are well-known features of temporal lobe epilepsy that may contribute to epileptogenesis. However, the mechanisms underlying glia activation are not well ...understood. Long non-coding RNA (lncRNA) H19 has diverse functions depending on physiological or pathological state, and its role in epilepsy is unknown. We previously demonstrated that H19 was significantly upregulated in the latent period of epilepsy and may be associated with cell proliferation and immune and inflammatory responses. We therefore speculated that H19 is involved in the hippocampal glial cell activation during epileptogenesis.
H19 was overexpressed or knocked down using an adeno-associated viral vector delivery system. A rat status epilepticus model was induced by intra-amygdala kainic acid injection. Astrocyte and microglia activation were assessed by immunofluorescence and western blot analyses. Expression of proinflammatory cytokines and components of the Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were evaluated with western blotting.
H19 overexpression induced the activation of astrocytes and microglia and the release of proinflammatory cytokines (interleukin-1β and interleukin-6 and tumor necrosis factor-α) in the hippocampus, whereas H19 knockdown inhibited status epilepticus-induced glial cell activation. Moreover, H19 activated JAK/STAT signaling by promoting the expression of Stat3 and c-Myc, which is thought to be involved in astrocyte activation.
LncRNA H19 contributes to hippocampal glial cell activation via modulation of the JAK/STAT pathway and could be a therapeutic tool to prevent the development of epilepsy.
Angiopoietin-like protein 4 (ANGPTL4) is a secretory glycoprotein involved in regulating glucose homeostasis in non-pregnant subjects. However, its role in glucose metabolism during pregnancy and the ...pathophysiology of gestational diabetes mellitus (GDM) remains elusive. Thus, this study aimed to clarify the relationship between ANGPTL4 and GDM and investigate the pathophysiology of placental ANGPTL4 in glucose metabolism. We investigated this issue using blood and placenta samples in 957 pregnant women, the human 3A-sub-E trophoblast cell line, and the L6 skeletal muscle cell line. We found that ANGPTL4 expression in the placenta was higher in obese pregnant women than in lean controls. Palmitic acid significantly induced ANGPTL4 expression in trophoblast cells in a dose-response manner. ANGPTL4 overexpression in trophoblast cells resulted in endoplasmic reticulum (ER) stress, which stimulated the expression and secretion of growth hormone-variant (GH2) but not human placental lactogen. In L6 skeletal muscle cells, soluble ANGPTL4 suppressed insulin-mediated glucose uptake through the epidermal growth factor receptor (EGFR)/extracellular signal-regulated kinases 1/2 (ERK 1/2) pathways. In pregnant women, plasma ANGPTL4 concentrations in the first trimester predicted the incidence of GDM and were positively associated with BMI, plasma triglyceride, and plasma GH2 in the first trimester. However, they were negatively associated with insulin sensitivity index ISI
in the second trimester. Overall, placental ANGPTL4 is induced by obesity and is involved in the pathophysiology of GDM via the induction of ER stress and GH2 secretion. Soluble ANGPTL4 can lead to insulin resistance in skeletal muscle cells and is an early biomarker for predicting GDM.
•A parametric study is performed on the operation of a planar membrane humidifier.•The simulations are performed for both counter-flow and parallel-flow arrangements.•There is no major difference ...between pressure drops of two arrangements.•Water recovery ratio of counter-flow arrangement is larger than that of parallel one.
In this paper, a parametric study is performed on the operation of a planar membrane humidifier (PMH) for the proton exchange membrane fuel cell. The numerical method is used to simulate the heat and mass transfer in the PMH. The simulations are carried out for both counter-flow and parallel-flow arrangements. The effects of different parameters including the inlet temperatures of wet and dry channels and the inlet mass flow rates of these channels on the pressure drop, dew point approach temperature, and water recovery ratio inside the PMH are studied. The results indicate that the counter-flow arrangement provides larger values of the water recovery ratio in comparison with the case of parallel-flow one. For the counter-flow arrangement, the dew point approach temperature is decreased about 49.6% as the inlet temperature of dry channel increases in the range of 20 °C to 50 °C at inlet mass flow rate of the wet channel m˙w,i=9 × 10−6 kg/s, inlet mass flow rate of the dry channel m˙d,i=18 × 10−6 kg/s, and inlet temperature at the wet channel Tw,i = 80 °C. There is no major difference between the pressure drops of parallel-flow and counter-flow arrangements.
Lanzhou lamb rotavirus vaccine (LLR) is an oral live attenuated vaccine first licensed in China in 2000. To date, > 60 million doses of LLR have been distributed to children. However, very little is ...known about faecal shedding of LLR in children. Therefore, faecal samples (n = 1,184) were collected from 114 children for 15 days post-vaccination in September-November 2011/2012. Faecal shedding and viral loads were determined by an enzyme immunoassay kit (EIA) and real-time RT-PCR. The complete genome was sequenced and the vaccine strain was isolated by culture in MA104 cells. Approximately 14.0% (16/114) of children had rotavirus-positive samples by EIA for at least 1 day post-vaccination. Viral loads in EIA-positive samples ranged from < 1.0 × 10
to 1.9 × 10
copies/g. Faecal shedding occurred as early as post-vaccination day 2 and as late as post-vaccination day 13 and peaked on post-vaccination day 5-10. One LLR strain was isolated by culture in MA104 cells. Sequence analysis showed 99% identity with LLR prototype strain. Faecal shedding of LLR in stool is common within 15 days of LLR vaccination, indicating vaccine strains can replicate in human enteric tissues.
Osteoporosis is characterized by low bone mineral density and microarchitectural deterioration of bone tissue. N‐(3‐methoxybenzyl)‐(9Z,12Z,15Z)‐octadecatrienamide (MBOC) is one of the macamides ...isolated from Maca (Lepidium meyenii Walp.), a cruciferous plant from the Andes of Peru. In this study, C3H/10T1/2 mesenchymal stem cells were treated with MBOC in osteogenic induction medium. An ovariectomized (OVX) mouse model was used to investigate the effect of 1‐month MBOC treatment on the prevention of postmenopausal osteoporosis. Remarkably, trabecular thickness, trabecular number, and bone volume/tissue volume of the distal femoral metaphysis were significantly increased in OVX + MBOC mice compared with OVX mice, as revealed by microcomputed tomography analysis. Trabecular separation was decreased in OVX + MBOC mice compared with OVX mice. Consistently, MBOC increased the levels of osteocalcin and runt‐related transcription factor 2 in OVX mice, as well as the expression of runt‐related transcription factor 2, osterix, and alkaline phosphatase in C3H/10T1/2 cells. Mechanistically, MBOC activates the canonical Wnt/β‐catenin signaling pathway via inhibiting phosphorylation of GSK‐3β at Tyr216 and maintaining β‐catenin expression. Collectively, the current study demonstrates the robustness of MBOC in the induction of mesenchymal stem cells osteogenic differentiation and consequent bone formation, suggesting that MBOC may be a potentially effective drug to treat postmenopausal osteoporosis.
N‐(3‐methoxybenzyl)‐(9Z,12Z,15Z)‐octadecatrienamide (MBOC) promotes differentiation of mesenchymal progenitor cells into osteoblasts by increasing Runx2, Osx, and Ocn expression via activation of the canonical Wnt/β‐catenin signaling pathway.
Abstract
Context
Maternal lipids during pregnancy and placental growth factors are associated with excess fetal growth. However, how these factors interact to increase the risk of delivering ...large-for-gestational-age (LGA) neonates remains unclear. In this study, we investigated the relationship between maternal plasma triglycerides (TGs) and free fatty acids (FFAs) during pregnancy, cord blood insulin-like growth factors (IGF), and LGA.
Objective
In a cell model, we studied the effect of different FAs on placental IGF-1 secretion.
Methods
This cohort study included pregnant women with term pregnancy and without diabetes or hypertensive disorders in pregnancy. Maternal fasting plasma TGs and FFAs were measured in the second trimester. Cord blood IGF-1, IGF-2, and IGF binding protein-1 and protein-3 were measured at the time of delivery. A human trophoblast cell line, 3A-sub-E, was used to evaluate the effect of different FFAs on placental IGF-1 secretion.
Results
We recruited 598 pregnant women–neonate pairs. Maternal plasma TG (180 mg/dL 152.5-185.5 mg/dL vs 166 mg/dL 133-206 mg/dL, P = .04) and cord blood IGF-1 concentrations (72.7 ± 23.0 vs 54.1 ± 22.8 ng/mL, P < .001) were higher in the LGA group and were significantly associated with birth weight z score. Maternal plasma free palmitic acid (PA) and stearic acid (SA), but not oleic acid (OA) or linoleic acid (LA), were significantly associated with cord blood IGF-1 concentrations. In 3A-sub-E cells, treatment with PA, SA, and LA, but not OA, induced IGF-1 expression and secretion.
Conclusion
Certain FFAs can induce placental IGF-1 secretion, which suggests a potential pathophysiology linking maternal plasma lipids and LGA.
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