Decreasing
the reduction temperature of an oxygen carrier is the key to reduce
energy consumption further and avoid the operational difficulties
of chemical looping air separation (CLAS). The copper manganese composite
oxygen carrier with zirconia as an inert binder, which has a relatively
low temperature of oxygen uncoupling, was developed. In the packed-bed
reactor, effects of several important operating parameters, viz.,
the feed gas rate, temperature, and inlet oxygen concentration, on
the separation reactivity were discussed. At higher reaction temperatures,
the reduction reactivity increases but the oxidation reactivity decreases.
In comparison to a copper oxygen carrier, the equilibrium oxygen concentration
of the copper manganese oxygen carrier is greatly enhanced. High gas
flow rates can accelerate the separation reaction. In the reduction
step, a lower oxygen concentration leads to a higher reduction reactivity.
In the oxidation step, the higher oxidation reactivity requires higher
oxygen concentrations. The oxygen uncoupling kinetics was determined
by the lnln kinetic method. The separation activation energy was determined
at 162.95 kJ mol–1, and the most likely mechanism
function is the unreacted shrinking core model (R
2). The main compositions in fresh and oxidized composite
oxygen carriers are Cu
x
Mn3–x
O4 and ZrO2. After reduction,
the active phase compositions are transformed into Cu
x
Mn2–x
O2. The inert phase of ZrO2 is stable during the redox reaction.
The repeated separation capability of the composite oxygen carrier
over 20 consecutive redox cycles is high.
This work proposes a chemical looping method to achieve the coproduction of N2 and H2. The system include a fuel reactor, a H2 generator and a N2 generator. Thermodynamics analysis is carried out to evaluate the feasibility of this method. In the fuel reactor, when the reaction temperature is 1000°C, 1.067kmol Fe and 0.851kmol FeO can be transported to the H2 generator and 2.991kmol syngas is produced. In the H2 generator, when the reaction temperature is 500°C, 0.223kmol Fe, 0.485kmol FeO and 0.425kmol Fe3O4 can be transported to the N2 generator and 1.250kmol H2 is produced. In the N2 generator, when the reaction temperature is 600°C, 1kmol Fe2O3 can be transported to the fuel reactor and 1.484kmol N2 is produced.
Previous studies have revealed that brain-derived neurotrophic factor (BDNF) levels are inversely associated with the severity of depressive symptoms. In addition, serum BDNF levels tend to increase with improvement in depressive symptoms. There is also evidence that BDNF has a possible role in the pathophysiology of schizophrenia. Therefore, the purpose of this study was to determine whether BDNF levels correlated with depressive symptoms in patients with first-episode and drug-naïve (FEDN) schizophrenia. In this study, 90 patients with FEDN schizophrenia and 60 healthy controls were recruited. The Positive and Negative Syndrome Scale (PANSS) and the 17-item Hamilton Depression Scale (HAMD-17) were used to gage psychopathological and depressive symptoms, respectively. All participants had their BDNF levels measured using a sandwich enzyme-linked immunosorbent test. Serum BDNF levels were lower in patients with FEDN schizophrenia compared with healthy controls. Moreover, patients with depressive symptoms exhibited a higher PANSS total score and a higher general psychopathology score than those without depressive symptoms (p < 0.05). For patients with depressive symptoms, serum BDNF levels were higher than in those without depressive symptoms (p < 0.05). An association between BDNF levels and the positive subscore was also observed (p < 0.01). However, there was no significant association between BDNF levels and HAMD scores (p > 0.05). In conclusion, BDNF levels were shown to be higher in the serum of patients with FEDN schizophrenia with depressive symptoms than in those without. Additionally, low levels of serum BDNF may contribute to the positive symptoms of FEDN schizophrenia but not to depressive symptoms.
Background
Recent studies have reported that psychotic symptoms are common in patients with major depressive disorder (MDD). However, few studies have reported the relationship between thyroid function, lipid metabolism and clinical profiles in female MDD patients. Thus, this study aimed to investigate the prevalence of psychotic depression (PD) and its risk factors in first-episode and drug naive (FEDN) depression among the female population in China.
Methods
This was a cross-sectional study involving a representative probability sample of 1,130 FEDN female outpatients with MDD (aged 18 years or older) in China. We collected information relating to socio-demographic characteristics, clinical data and blood samples. The Hamilton Depression Rating Scale 17-item version (HAMD-17), Hamilton Anxiety Rating Scale 14-item version (HAMA-14), and Positive and Negative Syndrome Scale (PANSS) were used to evaluate depressive, anxiety, and psychotic symptoms.
Results
The prevalence of psychotic symptoms in female MDD patients was 10.97%. The findings revealed significant differences between MDD female patients with psychotic symptoms and non-PD female patients in the following areas: higher HAMD scores, higher HAMA scores, more severe anxiety and an increased risk of suicide attempts. Further logistic regression analysis showed that psychotic symptoms were associated with higher thyroid-stimulating hormone (TSH) levels and an odds ratio of 1.168.
Conclusions
Our findings supported the hypothesis that higher TSH levels were correlated with psychotic symptoms in female MDD patients. Therefore, serum TSH levels may be a potential biomarker of PD in female MDD patients. In addition, we found that PD was closely associated with suicide attempts and lipid levels, but did not reach statistical significance.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.