共查询到20条相似文献,搜索用时 110 毫秒
1.
DDHI-DIPP二元体系固液平衡数据的测定和关联 总被引:5,自引:0,他引:5
测定了DDHI-DIPP体系的固液平衡相图,用理想溶液模型和UNIQUAC活度系数模型进行了关联;其中用UNIQUAC活度系数模型所获得的结果较满意。 相似文献
2.
用自制的汽液平衡釜测定了水—1,2-丙二醇二元体系在101.325kPa下全浓度范围的汽液平衡数据。所测数据通过了热力学一致性校验;并用最小二乘法回归Wilson和NRTL方程参数,由于所测温度范围较宽,参数表示为温度的线性关系进行拟合,所得计算值与实验值符合良好。 相似文献
3.
4.
5.
6.
以丙二酸二乙酯为原料,经亚硝化、还原、乙酰化、缩合、水解、脱羧反应制得3-(2-氧代-1,2-二氢喹啉-4-基)丙氨酸,总收率为41.5%,含量为98.7%.合成工艺简单易操作,适合工业化生产. 相似文献
7.
8.
研究了在模拟加氢反应器工况条件下,国产加氢反应器壁材料2(1/4)Cr-1Mo钢的断裂特性。应用断裂力学方法,分别测定了原始状态、原始+电化学渗氢、步冷状态、步冷+热渗氢试样的断裂韧性KIC;计算了埋入裂纹和表面裂纹的裂纹尖端的应力强度因子KI。结果表明:步冷处理提高了2(1/4)Cr-1Mo钢的断裂韧性,氢降低了2(1/4)Cr-1Mo钢的断裂韧性;只要反应器内壁无表面裂纹,设备运行是安全的。 相似文献
9.
10.
11.
Yali Hu Jianjun Zhou Sha Hao Zhiqun Wang Yiming Dai Jingxian Ling Yayi Hou 《International journal of molecular sciences》2007,8(6):492-504
It has been suggested that natural killer (NK) cell activity and Th1 immunity may be involved in the pathogenesis of preeclampsia. This study aimed to investigate the immunophenotypes of NK cells and type 1/type 2 immunity in both decidua and maternal peripheral blood between normal (n=11) and preeclamptic pregnant women (n=20) by flow cytometry. The results showed that no significant difference was observed between patients and controls by detecting CD56+CD69+ and CD56+CD94+ NK cells in both peripheral blood and decidua. Moreover, in preeclamptic patients, decreased percentages of Tc2 and Th2 cells and the increased ratios of Tc1/Tc2 were determined in both decidua and maternal peripheral blood. In addition, the ratio of Th1/Th2 in peripheral blood also increased. There was no significant difference of immunophenotypes of uNK cells between preeclampsia and normal pregnancy. Local decidua and systematic immunity did not correlate with each other. These results suggest that the type 1/type 2 immunity shifted to type 1 immunity including Th1 and Tc1 cells may contribute to the patho-genesis of preeclampsia. 相似文献
12.
Hye-Soo Park Seunga Choi Yong-Woo Back Kang-In Lee Han-Gyu Choi Hwa-Jung Kim 《International journal of molecular sciences》2021,22(14)
Prostaglandin E2 (PGE2) is an important biological mediator involved in the defense against Mycobacterium tuberculosis (Mtb) infection. Currently, there are no reports on the mycobacterial components that regulate PGE2 production. Previously, we have reported that RpfE-treated dendritic cells (DCs) effectively expanded the Th1 and Th17 cell responses simultaneously; however, the mechanism underlying Th1 and Th17 cell differentiation is unclear. Here, we show that PGE2 produced by RpfE-activated DCs via the MAPK and cyclooxygenase 2 signaling pathways induces Th1 and Th17 cell responses mainly via the EP4 receptor. Furthermore, mice administered intranasally with PGE2 displayed RpfE-induced antigen-specific Th1 and Th17 responses with a significant reduction in bacterial load in the lungs. Furthermore, the addition of optimal PGE2 amount to IL-2-IL-6-IL-23p19-IL-1β was essential for promoting differentiation into Th1/Th17 cells with strong bactericidal activity. These results suggest that RpfE-matured DCs produce PGE2 that induces Th1 and Th17 cell differentiation with potent anti-mycobacterial activity. 相似文献
13.
Hong-Jai Park Hyeon-Soo Park Jae-Ung Lee Alfred L. M. Bothwell Je-Min Choi 《International journal of molecular sciences》2016,17(8)
Peroxisome proliferator-activated receptor gamma (PPARγ) has recently been recognized to regulate adaptive immunity through Th17 differentiation, Treg functions, and TFH responses. However, its role in adaptive immunity and autoimmune disease is still not clear, possibly due to sexual differences. Here, we investigated in vitro treatment study with the PPARγ agonist pioglitazone to compare Th1, Th2, and Th17 differentiation in male and female mouse splenic T cells. Pioglitazone treatment significantly inhibited various effector T cell differentiations including Th1, Th2, and Th17 cells from female naïve T cells, but it selectively reduced IL-17 production in male Th17 differentiation. Interestingly, pioglitazone and estradiol (E2) co-treatment of T cells in males inhibited differentiation of Th1, Th2, and Th17 cells, suggesting a mechanism for the greater sensitivity of PPARγ to ligand treatment in the regulation of effector T cell differentiation in females. Collectively, these results demonstrate that PPARγ selectively inhibits Th17 differentiation only in male T cells and modulates Th1, Th2, and Th17 differentiation in female T cells based on different level of estrogen exposure. Accordingly, PPARγ could be an important immune regulator of sexual differences in adaptive immunity. 相似文献
14.
Kuo-Tung Tang Chi-Chien Lin Shih-Chao Lin Jou-Hsuan Wang Sen-Wei Tsai 《International journal of molecular sciences》2021,22(8)
Kurarinone is a flavanone, extracted from Sophora flavescens Aiton, with multiple biological effects. Here, we determine the therapeutic potential of kurarinone and elucidate the interplay between kurarinone and the autoimmune disease rheumatoid arthritis (RA). Arthritis was recapitulated by induction of bovine collagen II (CII) in DBA/1 mice as a collagen-induced arthritis (CIA) model. After the establishment of the CIA, kurarinone was given orally from day 21 to 42 (100 mg/kg/day) followed by determination of the severity based on a symptom scoring scale and with histopathology. Levels of cytokines, anti-CII antibodies, and the proliferation and lineages of T cells from the draining lymph nodes were measured using ELISA and flow cytometry, respectively. The expressional changes, including STAT1, STAT3, Nrf2, KEAP-1, and heme oxygenase-1 (HO-1) changes in the paw tissues, were evaluated by Western blot assay. Oxidative stress featured with malondiadehyde (MDA) and hydrogen peroxide (H2O2) activities in paw tissues were also evaluated. Results showed that kurarinone treatment reduced arthritis severity of CIA mice, as well as their levels of proinflammatory cytokines, TNF-α, IL-6, IFN-γ, and IL-17A, in the serum and paw tissues. T cell proliferation was also reduced by kurarinone even under the stimulation of CII and anti-CD3 antibody. In addition, kurarinone reduced STAT1 and STAT3 phosphorylation and the proportions of Th1 and Th17 cells in lymph nodes. Moreover, kurarinone suppressed the production of MDA and H2O2. All while promoting enzymatic activities of key antioxidant enzymes, SOD and GSH-Px. In the paw tissues, upregulation of Nrf-2 and HO-1, and downregulation of KEAP-1 were observed. Overall, kurarinone showed an anti-inflammatory effect by inhibiting Th1 and Th17 cell differentiation and an antioxidant effect exerted in part through activating the Nrf-2/KEAP-1 pathway. These beneficial effects in CIA mice contributed to the amelioration of their arthritis, indicating that kurarinone might be an adjunct treatment option for rheumatoid arthritis. 相似文献
15.
Fish oil supplementation of lactating mothers affects cytokine production in 2 1/2-year-old children
n−3 PUFA influence immune functioning and may affect the cytokine phenotype during development. To examine whether maternal
fish oil supplementation during lactation could modify later immune responses in children, 122 lactating Danish mothers with
a fish intake below the population median were randomized to groups supplemented for the first 4 mon of lactation with 4.5
g/d of fish oil (equivalent to 1.5 g/d of n−3 long-chain PUFA) or olive oil. Fifty-three mothers with a fish intake in the
highest quartile of the population were also included. The FA composition of erythrocyte membranes was measured at 4 mon and
at 2 1/2 yr. Plasma immunoglobulin E (IgE) levels and cytokine production in lipopolysaccharide-stimulated whole-blood cultures
were determined at 2 1/2 yr. Erythrocyte n−3 PUFA at 4 mon were higher in infants from the fish oil group compared with the
olive oil group (P<0.001) but were no longer different at 2 1/2 yr. The median production of lipopolysaccharide-induced interferon γ(IFN-γ)
in the fish oil group was fourfold higher than that in the olive oil group (P=0.034), whereas interleukin-10 (IL-10) production was similar. The IFN-γ/IL-10 ratio was twofold higher in the fish oil group
(P=0.019) and was positively correlated with 20∶5n−3/20∶4n−6 in erythrocytes at 4 mon (P=0.050). The percentages of atopic children and plasma IgE were not different in the two groups, but the study was not designed
to look at atopy. Cytokine responses and erythrocyte FA composition in children of mothers with a high fish intake were intermediate
in comparison with those in the randomized groups. Fish oil supplementation during lactation resulted in increased in vitro IFN-γ production in the children 2 yr after the supplementation was given, which may reflect a faster maturation of the immune
system. 相似文献
16.
以凹凸棒为载体,四氯化钛为钛源,通过溶胶-凝胶法结合超临界干燥法制备TiO2/凹凸棒复合光催化材料。采用XRD、SEM、TEM、BET、XPS等方法对材料的结构、形貌及催化性能进行表征。研究结果表明:超临界干燥可增大复合材料的比表面积,抑制TiO2发生晶型转变。凹凸棒吸附特性良好,增加了材料表面的活性位点,显著提高催化剂的光催化活性。不同煅烧温度下的TiO2均为锐钛矿型,粒径约为20 nm,呈不规则短棒状,成功负载于凹凸棒上。在400℃煅烧2 h条件下,催化剂3 h后对亚甲基蓝的降解率可达98.4%。 相似文献
17.
Xiaoxin Zhang Baoning Zong Minghua Qiao 《American Institute of Chemical Engineers》2009,55(9):2382-2388
In this article, we reported a nondestructive and environmentally friendly method for the reactivation of a spent Pd/AC catalyst for the hydrogenation of benzoic acid by using supercritical CO2 (scCO2) fluid extraction. The effects of reactivation conditions, such as extraction temperature, pressure, CO2 flow rate, and time, on the activity of the reactivated Pd/AC catalyst, were presented. The catalyst was characterized by N2 physisorption, laser particle size analysis, and transmission electron spectroscopy, and the liquid extract was analyzed by GC-MS. It is found that scCO2 fluid extraction was very efficient in eliminating organic substances blocking the pores of the catalyst, while did not affect noticeably the granule size of the catalyst and the particle size of Pd. The reactivated Pd/AC catalyst regained more than 70% of the activity of the fresh 5.0 wt % Pd/AC catalyst, and has been successfully used in an industrial unit for the hydrogenation of benzoic acid. © 2009 American Institute of Chemical Engineers AIChE J, 2009 相似文献
18.
Xinghai Liu Yifu ZhangShengping Yi Chi Huang Jun LiaoHoubin Li Di XiaoHongyun Tao 《The Journal of Supercritical Fluids》2011,56(2):194-200
V2O3 nanoparticles, with diameters of 30-60 nm, have been synthesized by supercritical ethanol fluid reduction of VOC2O4. It was found that the reaction time has little influence on the purity and morphology of as-prepared products. And carbon oxides decomposed from C2O42− were conducive to the formation of the uniform sphere-like nanoparticles. The reaction mechanism of synthesizing uniform V2O3 nanoparticles is believed to be the redox reaction between VOC2O4 and ethanol in the supercritical condition. The crystal growth mechanism was proposed on the basis of the discussion about the formation process of the uniform sphere-like nanoparticles. 相似文献
19.
Origin of Relaxor Behavior in K1/2Bi1/2TiO3–Bi(Mg1/2Ti1/2)O3 Investigated by Electrical Impedance Spectroscopy
下载免费PDF全文
![点击此处可从《Journal of the American Ceramic Society》网站下载免费的PDF全文](/ch/ext_images/free.gif)
Binbin Hu Mankang Zhu Jingjian Guo Ying Wang Mupeng Zheng Yudong Hou 《Journal of the American Ceramic Society》2016,99(5):1637-1644
Lead‐free binary K1/2Bi1/2TiO3‐Bi(Mg1/2Ti1/2)O3 (KBT‐BMT) ferroelectric ceramics with a morphology of dense and evenly sized grains have been prepared by conventional solid oxide reaction route. X‐ray diffraction analysis indicates that all the samples possess pure perovskite structure, and undergo a phase transformation from tetragonal to pseudocubic phase as BMT adds into KBT. Meanwhile, BMT addition brings in the enhancement of the relaxor behavior as revealed by temperature‐dependent dielectric profiles and the P–E loops. The impedance analysis reveals that the relaxation process existing in the ceramics belongs to a localized species. Further, in the frequency‐dependent M″(f) spectra, a shoulder response emerges accompanied by a bulk response as suitable amount of BMT is added, and its frequency dependence obeys Vogel–Fulcher relation f = f0 exp[ ‐ Eb/kB(T ‐ TVF)]. The shoulder response is believed to be the evidence of the existence of the polar nanoregions, which dominate the relaxor behavior of KBT‐BMT ceramics. 相似文献
20.
《Ceramics International》2022,48(15):21201-21208
A2Mo3O12 (A-Al, Fe, Cr) have large negative thermal expansion (NTE) coefficients and structural stability but high phase-transition temperatures (PTTs). Herein, we prepared (Al1/3Fe1/3Cr1/3)2(Mo1/2W1/2)3O12 (AFCMW), and found it to have a low NTE coefficient and a low PTT. Furthermore, combination of AFCMW with (Co1/2Ni1/2)(Mo1/2W1/2)O4 (CNMW) afforded an AFCMW–CNMW composite with a low thermal expansion (LTE). We determined that the PTT reductions in A2Mo3O12 are largely due to the high-entropy effect resulting from the introduction of different ions into its A and M sites. Moreover, we found that the low LTE of the AFCMW–CNMW composite is attributable to the opposite thermal expansion behaviours of AFCMW and CNMW. We suggest that the suppressed thermal expansion during the phase transition process of the AFCMW–CNMW composite could be derived from the high-entropy effect resulting from its increased diversity of polyhedra, the influence of Co2+ and Ni2+ dopants, and CNMW-induced lattice distortion. 相似文献